01 -
In a large mixing bowl, combine the ground meat, chopped spinach, minced garlic, Parmesan cheese, breadcrumbs, egg, Italian seasoning, salt, and pepper. Mix until well combined but do not overmix.
02 -
Take about 2 tablespoons of the meat mixture and flatten it in your palm. Place a mozzarella cube in the center, then fold the meat around it, sealing the edges to completely enclose the cheese. Roll into a smooth ball. Repeat with the remaining meat mixture and mozzarella cubes to form about 12 meatballs.
03 -
Heat olive oil in a large skillet over medium heat. Add the meatballs and cook for 2-3 minutes per side, until browned all over. Lower the heat and cover the skillet. Cook for an additional 8-10 minutes, or until the meatballs are fully cooked (internal temperature of 165°F/74°C).
04 -
If using marinara sauce, pour it into the skillet with the meatballs and simmer for 5 minutes to coat the meatballs and heat the sauce. Serve warm, garnished with extra Parmesan cheese and fresh parsley if desired.