My Favorite Green Bean Casserole

2 tablespoons butter

½ cup diced onion

1 tablespoon minced fresh flat-leaf parsley

1 cup diced fresh mushrooms

2 tablespoons all-purpose flour

1 teaspoon salt

½ teaspoon ground black pepper

½ teaspoon fresh lemon juice

1 cup sour cream

2 (14.5 ounce) cans French-style green beans, drained

1 cup shredded Cheddar cheese

1 cup crushed buttery round crackers

¼ cup melted butter

Preheat an oven to 350 degrees F (175 degrees C).

Melt 2 tablespoons butter in a skillet over medium heat. Cook and stir the onions, parsley, and mushrooms in the melted butter until the onions are translucent and the mushrooms are giving off their juices, 7 to 10 minutes. Add the flour, salt, pepper, and lemon juice; cook until the flour is slightly browned, 2 to 3 minutes. Stir the sour cream into the mixture. Mix the green beans into the mixture. Pour the green bean mixture into a 9-inch square baking dish. Sprinkle the Cheddar cheese over the mixture. Stir the crackers and melted butter together in a small bowl until evenly mixed; spread evenly over the Cheddar cheese layer.

Bake in the preheated oven until bubbly and brown, 20 to 30 minutes.