Step 1: Preheat the Oven

Set your oven to 350°F (175°C). Greasing your loaf pan in advance will make cleanup easier and ensure the meatloaf releases cleanly.

Step 2: Caramelize the Onions

Heat the olive oil in a wide skillet over medium-low heat. Add the thinly sliced onions and cook slowly, stirring occasionally, until the onions turn golden brown and caramelized. This process takes about 30–40 minutes but is essential for deep flavor. Patience pays off!

Step 3: Prepare the Meat Mixture

In a large mixing bowl, combine the ground beef, breadcrumbs, shredded Gruyère cheese, egg, Worcestershire sauce, thyme leaves, minced garlic, salt, and pepper. Gently mix everything together until just combined. Over-mixing can make the meatloaf dense, so mix with care.

Step 4: Shape the Meatloaf

Transfer the mixture into your greased loaf pan, pressing it gently to fill the pan evenly.

Step 5: Add the Caramelized Onions

Spread the caramelized onions over the top of the meatloaf, pressing them lightly so they adhere.

Step 6: Bake

Bake in the preheated oven for about 60 minutes, or until an internal thermometer reads 160°F (71°C). The crust will be golden, and the cheese inside melted to perfection.

Step 7: Rest and Serve

Let the meatloaf rest for about 10 minutes after baking. This helps the juices redistribute, making for moist, flavorful slices. Slice and serve warm!