Fill a large bowl with equal parts ice and water and set aside.
Fill a large saucepan ⅔ full of water, bring to a boil and add 1 teaspoon kosher salt. Add 1 pound green beans. Return to a boil and cook for 3 minutes, until crisp-tender.
Shock the beans
Use tongs to transfer the beans to the ice bath. Submerge them and agitate with the tongs so they cool quickly and keep their bright green color. Leave them in at least 5 minutes, until cold to the core.
Stack several paper towels on the counter. Transfer the beans to the towels and gently blot them dry.
Wrap the beans in dry paper towels and place in a zip-top bag. Refrigerate until ready to heat, up to 3 days.
Finish the beans
Heat 2-3 teaspoons butter in a large skillet over medium heat. Add 1 large clove garlic and stir until fragrant, without browning.
Add the beans and toss with tongs to coat. Cover and heat 2 to 3 minutes, tossing once or twice, until hot.
Season with 2 teaspoons lemon juice, ¼ teaspoon kosher salt, and a pinch black pepper. Toss again, transfer to a serving dish and serve right away.
Video
Notes
Note: To test for doneness, use a pair of tongs to retrieve a bean from the pot and bite into it. It should be firm, but not hard, and shouldn't squeak when you chew it.Figure ¼ pound of beans per person. For a crowd, use a larger pot of water and plenty more ice so the bath stays icy cold.To freeze, spread the blanched, dried beans on a lined rimmed baking sheet so they aren't touching. Freeze at least 1 hour and up to 2, until solid, then transfer to a freezer-safe zip-top bag for up to 2 months.