Classic Green Bean Casserole

The components of the casserole can be prepared ahead of time. Store the bread-crumb topping in an air-tight container in the fridge and combine with the onions just before cooking. Combine the beans and cool sauce in a baking dish, cover with plastic wrap, and refrigerate for up to 24 hours. To serve, remove the plastic wrap and heat the casserole in a 425-degree oven for 10 minutes, then add the topping and bake as directed. This recipe can be halved and baked in a 2-quart (or 9-inch square) baking dish. If making a half batch, reduce the cooking time of the sauce in step 3 to about 6 minutes. (1 3/4 cups) and the baking time in step 4 to 10 minutes.

ingredients

Topping
4 slices white sandwich bread, each slice torn into quarters
2 Tbs unsalted butter, softened
1/4 tsp table salt
1/8 tsp ground black pepper
3 cups canned fried onions (about 6 oz)

Beans and Sauce
Table salt
2 lbs green beans, ends trimmed and halved
3 Tbs unsalted butter
1 lb white button mushrooms, stems trimmed, wiped clean and broken into 1/2-inch pieces
3 medium garlic cloves, minced or pressed through garlic press
Ground black pepper
3 Tbs unbleached all-purpose flour
1 1/2 cups low sodium chicken broth
1 1/2 cups heavy cream