Preheat the oven to 350 degrees F.
In a large bowl, whisk together the eggs, heavy cream, salt, and black pepper. Set aside.
In a small saute pan, heat 1 tablespoon of bacon grease over medium heat. Add onions and saute until softened. Add diced tomatoes and stir well. Set aside. Spray a 13 by 9-inch pan with non-stick spray.
Layer turkey in the bottom of the pan, cover with bacon and sauteed onion mixture. Cover filling ingredients with shredded cheeses. Pour egg mixture over all and press lightly to make sure all ingredients are coated with the egg mixture.
Bake until puffed and set, about 45 to 55 minutes. After about 30 minutes, rotate and cover with aluminum foil if the top looks brown. Cut into 8 large pieces and cover with Three Cheese Mornay Sauce.
Heat half-and-half in a small saucepan to 160 degrees F. Set aside.
Melt butter in medium heavy-bottomed saucepan. Add onion and saute until translucent. Add flour and whisk to combine. Lower heat and cook for about 1 minute. Pour heated half-and-half into the flour mixture, whisking constantly. Reduce heat and bring to a simmer. Whisk until mixture begins to thicken. Add remaining ingredients and stir well. Taste and adjust seasonings.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Lynn's Paradise Cafe, Kentucky