Spread mayonnaise on one side of each slice of toasted bread and cut into small pieces.
Arrange toast, mayonnaise side up, in a greased 8-inch square baking dish.
Top with cheese slices and bacon.
In a skillet, scramble eggs over medium heat until fully cooked. Place scrambled eggs over bacon. Top with tomato slices; set aside.
In a saucepan, melt butter. Stir in flour, salt and pepper until smooth. Gradually add milk. Bring to boil; cook and stir for 2 minutes or until thickened. Pour over tomatoes.
Sprinkle with cheddar cheese and onions. Bake, uncovered, for 10 minutes. Serve and top with avocado slices.
Notes
ADD YOUR FAVORITE VEGGIES: I love that you can add all your favorite veggies to this egg bake. I’ve added sautéed mushrooms, onions, green peppers and even zucchini.
TOPPINGS: I like to top this egg bake with avocado slices, but shredded cheese is all you really need.