- 3 tablespoons butter
- 3 tablespoons all-purpose flour
- 1 (10 ounce) can condensed cream of mushroom soup
- 1 (4 ounce) can water chestnuts, chopped
- 1/2 teaspoon dry mustard
- 5 hard-cooked eggs, sliced
- 2 (14.5 ounce) cans asparagus spears, drained, chopped
- 1 (3 ounce) can French-fried onion rings, chopped
- 1 cup grated Cheddar cheese
- Preheat oven to 350 degrees F (175 degrees C). Butter a casserole dish.
- Melt butter in a saucepan over medium heat; whisk in flour until smooth. Stir mushroom soup, water chestnuts, and dry mustard into butter mixture; cook, stirring often, until mixture is hot, about 3 minutes.
- Layer half the egg slices, half the asparagus, and half the soup mixture in the prepared dish; repeat layers. Sprinkle top of casserole evenly with onion rings; sprinkle cheese over onion rings.
- Bake in the preheated oven until bubbly, about 30 minutes.