Creamy Scalloped Potatoes with Thyme
Inside: The simple layering method that keeps scalloped potatoes creamy—not watery—plus the easy béchamel trick that guarantees a perfectly thick sauce every time.
Creamy scalloped potatoes don’t have to be complicated—this version keeps things simple and worth it. Thinly sliced potatoes are layered with a rich béchamel and fresh thyme for a subtle, savory depth.
This recipe skips the extras and focuses on technique, so the potatoes cook evenly and stay tender without falling apart. The sauce thickens right in the pan, coating every slice for that classic creamy texture.
It’s a reliable side for holidays, Sunday dinners, or anytime you need something that pairs with just about everything—from rack of lamb, baked ham shank, various incarnations of pork tenderloin, even grilled veal chops and swordfish.
Creamy Scalloped Potatoes Everyone Asks For
When my extended family gets together for occasions like Christmas, Easter or Thanksgiving, everyone brings something. My grandfather handles the roast, RoseMarie makes the ratatouille, and Katrina’s in charge of dessert.
Me? I’m always asked to bring the creamy scalloped potatoes. They may sound simple, but sometimes that’s exactly what you want—something familiar that delivers every time.
Why this recipe works:
- Built-in creamy sauce (no shortcuts) – Adding milk a little at a time, rather than all at once, ensures the sauce thickens properly from the start, so you don’t end up with watery or broken layers or lumps.
- Layering = even cooking – Thinly sliced potatoes and consistent layering help everything cook at the same rate, so you get tender slices all the way through.
- Rich but not heavy – I skip heavy cream in favor of milk, to create a creamy dish that tastes rich and velvety—but isn’t coma-inducing.
- Fresh thyme keeps it from feeling flat – A touch of fresh herbs cuts through the creaminess and gives the dish a subtle, savory depth.
- Covered, then uncovered bake – Tenting traps steam to cook the potatoes through, then removing the foil lets the top set and lightly brown.
Ingredients:
- Potatoes – The foundation of the dish. Use a waxy variety (like Yukon Gold) for slices that hold their shape and turn tender rather than mushy. You can also use russet potatoes for a fluffier texture; just peel them first.
- Butter – Starts the béchamel and adds richness. It also helps carry the flavor throughout the layers.
- Flour – Combined with butter to form a roux, which thickens the sauce so it clings to the potatoes instead of turning watery.
- Milk – Creates the creamy béchamel. Whole milk gives the best balance of richness without being too heavy. You can also use 2%. I don’t use half-and-half or heavy cream, because it’s redundant in the bechamel.
- Onion – Adds a subtle savory sweetness as it bakes into the layers. It shouldn’t overpower—just enhance.
- Dry Mustard Powder–adds depth. Don’t substitute yellow or Dijon mustard.
- Fresh thyme – Brings a light, earthy note that lifts the richness of the cream and butter. A little goes a long way.
- Salt – Essential for seasoning every layer so the potatoes don’t taste flat.
- Black pepper – Adds mild heat and balances the creaminess.
- Vegetable spray or oil – Keeps the dish from sticking and makes serving easier.
Step-by-step instructions:
(pardon our dust–my process shots haven’t been updated yet).
- Melt the butter in a medium saucepan over medium to medium-high heat. Whisk in the mustard powder and salt until all the ingredients are moist and no dried bits remain.
2. Add the milk a little at a time, stirring constantly and scraping the sides so the flour mixture doesn’t stick or burn. The mixture will be very thick with the first few additions, but will begin to thin after all the milk is added. Continue cooking, stirring constantly until the bechamel comes to a boil. Cook one minute until the sauce thickens and remove from the heat; stir in the fresh thyme.
3. Spray the casserole dish with vegetable spray. Add a few spoonfuls of the bechamel and spread it over the bottom of the casserole dish. Sprinkle with a handful of diced onions.
4. Add a single layer of potatoes, overlapping them slightly and spoon over more of the bechamel sauce. Sprinkle with onions and continue layering in this manner until everything is used up, but a few spoonfuls of sauce remain.
5. Spread the remaining sauce over the potatoes and dot with butter. Place the casserole on a sheet pan to catch any spills. Cover with foil and bake.
6. Bake at 375°F for 45 minutes, remove the foil and reduce the heat to 350°F. Bake an additional 30 minutes to finish cooking and brown.
Pro-Tips:
- Make sure you save a few spoonfuls of the sauce to top the creamy scalloped potatoes after they’re layered in the dish.
- If the bechamel is too thick, add a few more tablespoons of milk into it and whisk until it’s combined.
- You can use a sharp chef’s knife to slice the potatoes, but the slicing attachment on your food processor or a mandoline slicer will make quicker work of it.
- Cover the casserole with aluminum foil for the first 45 minutes of baking to help it cook. Remove it for the last 30 minutes to brown.
Swaps and Variations:
- Add some shredded cheddar, Gruyere or other cheese to the sauce after you’ve removed it from the heat. Whisk until it melts–now you have au gratin potatoes.
- Add 2 garlic cloves, minced, to the butter when making the bechamel sauce for more flavor and depth.
- Add bits of ham, chicken or sausage to make a complete meal.
- Bake in 1-cup ramekins for individual servings.
- Make it vegan by swapping milk for vegetable broth.
FAQs
The sauce is what makes them creamy; a proper bechamel (which doesn’t necessarily contain cream) is about being thick enough to cloak the potatoes without being gluey. The ratio of sauce to potatoes is also impactful.
I prefer whole or 2% milk as the base. Adding half-and-half or cream can make them too filling, whereas with milk, it tastes rich and indulgent without filling you up after a few bites.
Make ahead:
- You can assemble the this potato recipe earlier in the day and keep covered and refrigerated.
- Remove the creamy scalloped potatoes from the refrigerator half an hour before baking to let them come to room temperature, or you may need to increase the baking time.
Storage:
- Store leftovers well wrapped in plastic wrap in the fridge for 3-5 days.
Reheating:
- Reheat for 15-20 minutes in a 350°F oven, until hot and bubbly.
Freezing:
- You can freeze the baked casserole, well wrapped in plastic wrap and freezer paper, for up to 2 months.
- Defrost to reheat.
More potato side dishes you’ll love:
- Loaded Potato Salad
- Colcannon Cakes
- Crispy Breakfast Potatoes
- Creamy Whipped Sweet Potatoes
- Roasted Duck Fat Potatoes
- Southern French Potato Salad
- Brown Butter Sea Salt Mashed Potatoes
- Homemade French Fries
- Mustard Roasted Potatoes
- Leftover Mashed Potato Souffle
- Twice Baked Sweet Potato Gratin
- Roasted Turnips Potatoes and Greens
Creamy Scalloped Potatoes with Thyme
INGREDIENTS:
- 3 tablespoons + 1 teaspoon butter divided
- 3 tablespoons flour
- 1 teaspoon dry mustard
- 1 teaspoon kosher salt
- 2 cups milk
- ½ teaspoon black pepper freshly ground
- 1 tablespoon thyme leaves chopped fresh
- 2 pounds yukon gold potatoes peeled and thinly sliced crosswise
- 1 medium onion diced
DIRECTIONS:
- Preheat oven to 375℉.
- Place a saucepan over medium heat and add 3 tablespoons butter. Using a whisk, swirl the butter around in the pan until it's almost melted.
- Add 3 tablespoons flour and stir briskly to incorporate the flour and butter. Sprinkle in 1 teaspoon dry mustard and 1 teaspoon kosher salt and continue to cook for one minute over medium heat.
- Whisk in 2 cups milk adding it slowly, a little at a time, making sure it's completely blended with the roux before adding more. Continue to stir until the liquid comes to a rolling boil. Constantly stir and scrape the bottom of the pan while the sauce continues to cook and thicken, about 1 minute.
- Add 1 tablespoon thyme leaves and ½ teaspoon black pepper. Remove from heat and set aside.
- Dice 1 medium onion and slice 2 pounds yukon gold potatoes
- Spray an 8×8" baking dish with vegetable spray. Spoon 2-3 tablespoons of the béchamel (milk mixture) into the bottom of the dish.
- Sprinkle lightly with a handful of onion. Arrange 2 pounds yukon gold potatoeshe potato slices in a single layer, overlapping them in the casserole dish. Sprinkle with ⅓ of the onions. Pour ¼ of the béchamel evenly over the potatoes. Continue layering in the same manner: Potatoes, onions, béchamel; potatoes, onions, béchamel. Finish with a layer of potatoes, topped by the last bit of béchamel.
- Dice the last teaspoon of butter and dot it over the top of the casserole.
- Place the baking dish onto a rimmed baking sheet. Spray one side a piece of tin foil with vegetable spray. Place the sprayed side of the foil over the potatoes and transfer the casserole to the hot oven. Set a timer for 45 minutes.
- After the timer goes off, reduce the heat to 350℉ and remove the tin foil. Continue to bake for an additional 30 minutes.
- Remove from the oven and cool for 5-10 minutes before serving.
NOTES:
- You can assemble the this potato recipe earlier in the day and keep covered and refrigerated.
- Remove the creamy scalloped potatoes from the refrigerator half an hour before baking to let them come to room temperature, or you may need to increase the baking time.
- Store leftovers well wrapped in plastic wrap in the fridge for 3-5 days.
- Reheat for 15-20 minutes in a 350°F oven, until hot and bubbly.
- You can freeze the baked casserole, well wrapped in plastic wrap and freezer paper, for up to 2 months.
- Defrost to reheat.
NUTRITION:
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Lisa, I’m excited to try this recipe! I have a question about the instructions – it says to set aside one tbsp of butter, but I couldn’t see where it’s supposed to be added back in. Looking at the pictures, it looks like you’ve added some butter to the top of the dish before it gets put in the oven – is this correct?
Yes, Roy – that’s exactly what I do. Just sprinkle a few dots over the casserole! I hope you enjoy it!
This looks incredible, Lisa! I am absolutely going to try these out soon.
This is probably one of my most popular recipes – for a reason — they’re delicious!
Can this dish be made ahead of time? Does it work warmed back up? Thanks!
That’s a great question, Mallory. Yes, it can be made ahead. Just stick the casserole into the refrigerator until about 2 hours before you want to eat. Let them sit on the counter for 20 minutes or so while the oven heats and then bake. They can be cooked and rewarmed as well, but I prefer them the first time around – and baked when I’m ready to eat.
So do I add the thyme and black pepper along with salt and mustard? I don’t see it anywhere in the instructions. Please and thank you
Beautiful and delicious! Great recipe for the upcoming holidays.
I concur!
I absolutely love potatoes, and funnily enough l was just thinking about making this dish today. I’ve never thought of adding onion, it must bring such a lovely flavour though. I really have to make it now!
These potatoes are a must for any family/friends/gathering!
I am prepared to fight for the crispy topping bits on a dish like this!
En garde!
This looks so creamy – wow – thought for sure there’d be cheese in it but delighted as there isn’t as I’m lactose intolerant and fake cheese isn’t yum at all but I can easily sub the milk. Love the idea of everyone bringing a dish – a family pot luck!
Ewww – I agree, fake cheese doesn’t do it for me either! Let me know how you like it! We usually divvy up responsibilities for all the family occasions – it makes it easier on everyone.
I will try this recipe with sweet potatoes as I don’t eat much potatoes. It looks very tasty!
I’ll bet it would be fantastic with sweet potatoes!
These look so divine! The epitome of comfort!
Oh this looks simply marvelous and I would SOOO toss in some Gruyere! Delicious!
Enjoy it, CC!
This dish looks gorgeous AND delicious! A perfect holiday side fit for any table! Can’t wait to try. XO
Another beautifully photographed recipe tutorial. Creamy potatoes are one of my weaknesses!
What a perfect Thanksgiving side!! Everyone’s favorite at my home too..
This is how a perfect side dish looks to me. I am a fan of potatoes, and if they are combined with fresh thyme… I am sold. Thanks for the great recipe!
I love potatoes, too — but we don’t eat them often, so this is a treat!
Wow, this recipe looks so amazing. Perfect for any gathering is right! Such a cozy, delicious, comfort food.
It was fabulous! Thanks. 🙂
So glad you enjoyed them!
Making today for Easter!!
Your notes should say this recipe can and should be doubled. I think we’ll be making these for Christmas.
Scalloped potatoes – one of my favorites! These look delish and such a perfect side dish.