This Classic Green Bean Casserole Is Exactly How You Remember It — Only Better

Make ahead: Assemble the casserole without the onion topping, cover, and refrigerate up to 1 day ahead. Let the casserole sit at room temperature while the oven heats. Uncover and top with the fried onions. Bake for 30 to 40 minutes, covering the top with aluminum foil in the final 10 minutes if the onions brown too quickly.

Substitutions: 3 (about 15-ounce) cans green beans can be substituted for the fresh green beans. Drain well before adding to the mushroom sauce.

Storage: Leftovers can be refrigerated in an airtight container for up to 4 days.