01 -
Preheat your oven to 180°C. Lightly grease a 9×13-inch baking dish.
02 -
In a large bowl, combine the ground beef, breadcrumbs, milk, egg, onion, garlic, salt, pepper, Worcestershire sauce, and ketchup. Mix until just combined. Press the meat mixture evenly into the prepared baking dish to form a flat layer.
03 -
Bake in the preheated oven for 15 minutes while preparing the mac and cheese topping.
04 -
In a medium saucepan, melt the butter over medium heat. Stir in the flour and cook for 1-2 minutes to create a roux. Gradually whisk in the milk, stirring constantly, until the mixture thickens (about 3-4 minutes). Remove from heat and stir in the cheddar cheese until melted and smooth. Add mustard powder if using. Season with salt and pepper to taste. Toss the cooked macaroni in the cheese sauce until well coated.
05 -
Remove the meatloaf base from the oven. Spread the mac and cheese evenly over the meatloaf. Sprinkle extra shredded cheddar cheese on top for a golden crust.
06 -
Return the dish to the oven and bake for an additional 20-25 minutes, or until the cheese is bubbly and golden.
07 -
Let the casserole rest for 5 minutes before slicing and serving. Pair with a fresh salad or steamed vegetables for a complete meal.