Preheat Oven: Preheat oven to 350°F (175°C). Grease a loaf pan or line with parchment paper.
Prepare Meat Mixture: In a large bowl, combine ground beef, ground pork, chopped mushrooms, onion, garlic, breadcrumbs, milk, eggs, salt, pepper, and Worcestershire sauce. Mix until evenly combined.
Form Meatloaf: Shape the mixture into a loaf and place in the prepared pan.
Add Cheese and Topping: Layer Swiss cheese over the top of the meatloaf. Spread ketchup or tomato sauce over the cheese.
Bake: Bake for 60–70 minutes, until the meatloaf is cooked through (internal temperature should reach 160°F / 71°C) and cheese is melted and golden.
Serve: Let the meatloaf rest for 5–10 minutes before slicing. Serve with mashed potatoes, roasted vegetables, or a fresh salad.
Serving and Storage Tips
