Spray a 2-quart rectangular baking dish with nonstick coating; set aside.
Snap off and discard woody bases from asparagus. Cut asparagus into 1- to 2-inch pieces (about 2 cups total); set aside. In a medium skillet, melt butter over medium heat. Add onion; cook for 3 minutes, stirring occasionally. Add asparagus and curry powder. Cook and stir for 2 to 3 minutes more or until onion and asparagus are just tender.
Arrange bread slices in bottom of prepared baking dish, cutting bread to fit if needed. Spoon asparagus mixture evenly over bread. Sprinkle cheese over top. In a medium mixing bowl combine milk, eggs, salt, and pepper. Pour over cheese. Bake in a 450 degree F oven for 15 to 20 minutes or until a knife inserted near the center comes out clean. Let stand for 5 to 10 minutes before serving. Makes 6 servings.