- 1 teaspoon vegetable oil
- 2 onions, sliced
- 8 slices rye bread
- 2 tablespoons Dijon mustard
- 1 1/2 cups shredded Cheddar cheese
- 1 large tomato, seeded and coarsely chopped
- 1 1/2 cups milk
- 4 eggs
- Heat oven to 300 degrees F. Spray square baking dish, 8x8x2 inches, with cooking spray. Heat oil in 10-inch nonstick skillet over medium-high heat. Cook onions in oil 6 to 8 minutes, stirring frequently, until golden brown; remove from heat.
- Trim crusts from bread. Spread mustard on 1 side of each bread slice. Arrange 4 slices, mustard sides up, in baking dish. Layer 1 cup of the cheese, the tomato and onions on bread. Place remaining bread, mustard sides down, on onions. Beat milk and eggs until well blended. Pour evenly over bread.
- Bake uncovered about 1 hour or until center is set and bread is golden brown. Sprinkle with remaining 1/2 cup cheese. Let stand 10 minutes before cutting.