Spinach Garlic Meatballs Stuffed with Mozzarella

Prepare the Meatball Mixture:

In a large bowl, combine the ground beef, chopped spinach, minced garlic, breadcrumbs, Parmesan cheese, egg, salt, black pepper, and Italian seasoning. Mix until just combined—avoid over-mixing to keep the meatballs tender.
Stuff with Mozzarella:

Take about 1-2 tablespoons of the meat mixture and flatten it in your palm. Place a cube of mozzarella cheese in the center, then carefully wrap the meat around it, sealing it completely. Roll into a ball. Repeat with the remaining meat mixture and cheese cubes.
Cook the Meatballs:

In a large skillet, heat the olive oil over medium heat. Add the meatballs in batches, ensuring not to overcrowd the pan. Cook for about 4-5 minutes per side, until browned on all sides and cooked through.
Serve:

Serve warm with marinara sauce for dipping or over pasta, and garnish with extra Parmesan and fresh basil, if desired.