Spinach Garlic Meatballs Stuffed with Mozzarella delight!

Preheat the oven to 400°F.
In a large bowl, combine ground beef, chopped spinach, breadcrumbs, Parmesan cheese, onion, garlic, egg, salt, pepper, and Italian seasoning. Mix until well combined.
Take a small amount of the meat mixture (about 2 tablespoons) and flatten it in your palm. Place a cube of mozzarella in the center and wrap the meat around it, forming a ball. Repeat with the remaining mixture.
Heat olive oil in a large oven-safe skillet over medium heat. Add the meatballs and cook for about 5 minutes, turning occasionally, until browned on all sides.
Pour marinara sauce over the meatballs in the skillet. Transfer the skillet to the preheated oven and bake for 15-20 minutes, or until the meatballs are cooked through and the cheese is melted.
Serve hot, garnished with additional Parmesan cheese if desired.

For a lighter version, substitute ground turkey or chicken for the beef.
Add chopped bell peppers or mushrooms to the meat mixture for extra flavor and nutrition.