For the Macaroni and Cheese Sauce Base: Melt butter in a 4-quart saucepot over medium high heat. Add flour and mix until flour is incorporated into butter. Cook, stirring frequently for 2 minutes. Add milk and chicken broth and continue to cook until sauce is thick and bubbly. Remove from heat and season with mustard, hot pepper sauce, Worcestershire, salt and pepper. Allow to cool before using.
For the Topping: Mix all ingredients in a bowl and set aside
For the Molten Cheese Sauce: Take about 1/2 cup of the sauce base and warm over a medium burner in a small saucepan. When warm, add cheese and cook until melted. Season as necessary.
To make the Macaroni and Cheese: Cook macaroni in salted water, drain and rinse with cold water. Place the yellow cheddar, Gruyere, white cheddar, tomatoes, and pasteurized prepared cheese product in a large mixing bowl. Add 3/4 of the macaroni and cheese sauce base or about 2 1/2 cups, and mix thoroughly. Place the mix evenly into 4 small casserole dishes or 1 large serving plate. Sprinkle with topping and bake in a preheated 400-degree oven until hot and bubbly. Make sure to serve lots of molten cheese sauce.