Step 1

Preheat the oven to 325 degrees F.

Step 2

Spread the mayonnaise on one side of each slice of the bread.

Step 3

Cut the mayonnaise-coated slices into bite-sized pieces.

Step 4

In an 8-inch square baking dish, arrange the mayonnaise-coated bread pieces, mayo side up.

Step 5

Top the bread pieces with the cheese slices and bacon.

Step 6

In a small saucepan, melt the butter.

Step 7

Stir the flour, salt, and pepper into the melted butter until smooth.

Step 8

Gradually add the milk to the butter mixture.

Step 9

Bring the butter mixture to a boil.

Step 10

Cook and stir the butter mixture until thickened, about 2 minutes.

Step 11

Pour the butter mixture over the bacon in the baking dish.

Step 12

In a large skillet over medium heat, fry the eggs until they have reached your desired doneness.

Step 13

Place the cooked eggs over the bacon in the baking dish.

Step 14

Top the eggs with the tomato and sprinkle with the shredded cheese and the onions.

Step 15

Bake, uncovered, until the cheese has melted and is slightly golden, about 10 minutes.

Step 16

Cut the bake into squares.

Step 17

Serve with lettuce.