Twice-Baked Sweet Potato Gratin

4.18 from 17 votes

Fluffy rosemary-and-Gruyère sweet potatoes baked in individual ramekins under a browned cheese crust, and you can fill them a day ahead.

Course Side Dish

Cuisine American

Keyword make ahead sweet potatoes, sweet potato casserole in ramekins, sweet potato gratin, twice baked sweet potato gratin

Prep Time 20

Cook Time 1 25

Total Time 1 45

Servings

Calories 257kcal

Preheat the oven to 375 degrees.
Place the potatoes on a baking sheet lined with aluminum foil and Bake at 375°F (or 400°F for large potatoes) for 45 to 75 minutes, until a knife slides through the thickest part with no resistance. Remove from the oven and cut each potato in half. Let the potatoes cool until you can handle them, then scoop out the flesh into a bowl.
Use a potato ricer or hand mixer to puree the potatoes. Stir in the rosemary, salt and pepper. Add the milk and butter and stir until butter has melted. Add 1 1/4 cups of gruyere and stir to combine. Set aside.
Spray 6 half-cup ramekins with vegetable spray. Divide the sweet potatoes among the ramekins and smooth the tops with the back of a spoon. Sprinkle with the remaining cheese.
Can be made in advance to this point and refrigerated until ready to bake.
To bake the gratins, preheat the oven to 350°. Place the gratins on a baking sheet and bake for 15 minutes until warmed through then turn on the broiler and cook for an additional 2-3 minutes until lightly browned. Serve.

Make ahead: Fill ramekins, cover and refrigerate up to [2 days]. Add [5 to 10] minutes to the bake time if baking straight from the fridge.
Casserole dish: Bake in a small greased dish for 25 to 30 minutes, then broil.
Leftovers: Already have baked sweet potatoes? Start at step 3.