Preheat your oven to 375°F (190°C) and gather a loaf pan for shaping.

Melt 2 tablespoons of butter in a skillet over medium heat, add onions, and cook until golden brown, around 15-20 minutes.

In a mixing bowl, combine ground beef, caramelized onions, breadcrumbs, eggs, shredded cheese, garlic, salt, and pepper. Mix until just incorporated.

Shape the meat mixture into a loaf in your baking dish. Bake for 50 to 60 minutes until the internal temperature reaches 160°F (70°C).

Allow the meatloaf to rest for 10 minutes before slicing and serving.