Prep the mozzarella: Cut the block into 3/4-inch cubes. Pat dry with a paper towel to reduce moisture and help prevent cheese leaks.

Make the meat mixture: In a large bowl, combine ground meat, egg, almond flour, Parmesan, garlic, onion, parsley, Italian seasoning, red pepper flakes, salt, and pepper. Mix with your hands until just combined. Don’t overwork it.

Portion the meatballs: Scoop about 2 tablespoons of mixture per meatball. You should get around 14–16 meatballs.

Stuff with cheese: Flatten a portion in your palm, place a mozzarella cube in the center, and wrap the meat around it. Roll gently to seal completely. Pinch any seams shut to keep cheese inside.

Chill briefly: Place stuffed meatballs on a plate and refrigerate for 10–15 minutes. This helps them hold shape during cooking.

Sear for flavor: Heat a large oven-safe skillet over medium-high with a thin layer of oil. Sear meatballs 1–2 minutes per side until browned. Work in batches so you don’t crowd the pan.

Bake to finish: Transfer the skillet to a 375°F (190°C) oven and bake 8–10 minutes, or until an instant-read thermometer reads 160°F (71°C). If you don’t have an oven-safe skillet, move them to a parchment-lined sheet after searing.

Warm the sauce: While they bake, heat your low-sugar marinara in a small pot. Taste and adjust seasoning with salt, pepper, and a splash of olive oil.

Serve: Spoon meatballs into warm marinara or pour sauce over the skillet. Garnish with basil or extra Parmesan. Enjoy hot while the centers are melty.