Cheesy Beef Grilled Cheese Sandwich with Caramelized Onions

Heat 1 tbsp olive oil in a skillet over medium-low heat. Add thinly sliced onions and cook for 8 to 10 minutes, stirring occasionally, until soft and golden brown. Transfer to a bowl.

In the same skillet, cook 1 lb ground beef over medium heat, breaking it apart until browned. Drain excess grease. Stir in garlic powder, onion powder, smoked paprika, Worcestershire sauce, salt, and pepper. Cook 1 to 2 minutes longer, then remove from heat.

Spread a thin layer of mayonnaise or softened butter on the outside of all 8 bread slices. Lay 4 slices butter-side down on your work surface. Layer each with:

1. 1 slice cheddar

2. Generous scoop of seasoned beef

3. Caramelized onions

4. 1 slice mozzarella/provolone

5. 1 slice cheddar

6. Top bread slice (butter-side facing up)

Preheat a heavy skillet or griddle over medium-low heat. Grill sandwiches for 3 to 4 minutes until bottom crust is deeply golden. Carefully flip and grill the second side for another 3 to 4 minutes until cheese is completely melted.

Transfer to a cutting board and let rest for 2 minutes before slicing in half diagonally. Serve warm with tomato soup or pickles.