Savory French Toast Casserole

Arrange half of the bread slices over the bottom of a buttered 9 by 11 inch baking dish. Cover with the cheese and scallions; then top with the remaining slices of bread.

Beat the eggs, milk, mustard, salt, and pepper together in a bowl. Pour the egg mixture over the bread, pressing the bread down lightly to be sure it absorbs the batter. Cover tightly and refrigerate for at least 1 hour or overnight.

Preheat the oven to 325 degrees F.

Bake the casserole, uncovered, until it is puffed and golden brown, 1 hour. Let it cool in the pan for 5 minutes before cutting, then serve immediately.

Variations:

HAM AND SWISS CASSEROLE: Use rye bread. Substitute Swiss cheese for the Gruyere and top it with a layer of thinly sliced ham.

GARLICKY MUSHROOM CASSEROLE: Saute 1/2 lb. thinly sliced mushrooms and 2 minced cloves of garlic in butter or olive oil. Spread the mushrooms over the Gruyere.

TEX-MEX CASSEROLE: Substitute pepper Jack for the Gruyere, and if you like, top it with a layer of crumbled cooked chorizo (a spicy Mexican sausage). Garnish each serving with sliced avocado, sour cream, and salsa.