Green Bean Casserole

Ingredients

0 of 14 out on the counter

• 2 lb green beans, trimmed and snapped in half
• 1 lb white mushrooms, sliced
• 3 tbsp olive oil, for the sauce
• 3 tbsp all-purpose flour
• 2 garlic cloves, minced
• 1 cup vegetable broth
• 1½ cups whole milk
• ½ tsp salt
• ¼ tsp black pepper
• a pinch of nutmeg
• 1 large onion, sliced thin
• 1 tbsp olive oil, for the onions
• ¼ tsp salt, for the onions
• salt for the bean water

All set! Everything is out. Time to bake.

Method

1. 1Heat the oven to 375 °F. Set a pot of salted water to boil.
2. 2Boil the beans 4 minutes, until bright green and just tender. Drain, and rinse with cold water so they stop cooking. Spread them in a 9 x 13-inch dish.
3. 3Toss the onion slices with the 1 tbsp olive oil and ¼ tsp salt; no flour. Roast them in one layer in the air fryer basket, in two batches if needed, at 370 °F for 10 to 12 minutes, shaking halfway, until deep golden at the edges. In the oven instead: spread on a lined sheet and roast at 425 °F for 20 to 25 minutes, tossing once.
4. 4Meanwhile, set a wide skillet on medium-high, add the 3 tbsp oil, and when it shimmers, cook the mushrooms 8 to 10 minutes, until they give off their liquid and brown. Add the garlic and cook 30 seconds.
5. 5Sprinkle in the flour and stir for 1 minute. Whisk in the broth, then the milk. Simmer, stirring, 3 to 4 minutes, until thick enough to coat a spoon. Season with ½ tsp salt, the pepper and the nutmeg.
6. 6Pour the sauce over the beans and stir to coat. Bake 20 minutes, until bubbling at the edges.
7. 7Pile the crisp onions on top and bake 5 minutes more. Serve warm.
8. 8Cool leftovers within 2 hours, then refrigerate. Reheat to 165 °F.