Preheat the oven to 350°F (175°C). In a large bowl, mix together ground filet, breadcrumbs, eggs, chopped onion, minced garlic, Worcestershire sauce, salt, and black pepper until well combined.

Shape and Bake

Form the mixture into a loaf shape and place it in a baking dish. Bake for 1 hour, or until the internal temperature reaches 160°F (70°C).

Make the Mashed Potatoes

While the meatloaf is baking, boil the cubed potatoes in salted water until tender, about 15-20 minutes. Drain and return to the pot. Add butter and milk, then mash until creamy. Season with salt to taste.

Prepare the Mushroom Demi-Glaze

In a skillet, sauté sliced mushrooms in a bit of oil until browned. Add beef broth and thyme; simmer until thickened, about 10 minutes.

Assemble the Dish

Serve slices of the meatloaf on plates with a side of mashed potatoes, topped with roasted red pepper rings and drizzled with mushroom demi-glaze.