Preheat your oven to 375°F (190°C) and grease a loaf pan or line a baking sheet with foil.

Cook bacon in a skillet over medium heat until crispy, about 6-8 minutes. Set it aside on paper towels. Sauté mushrooms in the bacon fat for about 5 minutes until browned.

In a mixing bowl, combine ground beef, eggs, breadcrumbs, onion, garlic, Worcestershire sauce, salt, and pepper. Mix until just combined.

Transfer the mixture to a greased loaf pan or baking sheet, shape it into a loaf, and create a well in the center. Layer with Swiss cheese, sautéed mushrooms, and bacon.

Bake in the preheated oven for 45-55 minutes until the internal temperature reaches 160°F (71°C). Cover with foil if browning too quickly.

Let the meatloaf rest for 10 minutes, slice carefully, and serve warm, garnished with parsley if desired.