Season the meatballs with salt and pepper. Place the meatballs in the air fryer.
Air fry on 380°F (195°C) for 8-12 minutes (depending on size), shaking the basket halfway through cooking.
To make the optional tomato sauce, add the diced tomatoes, tomato paste, and seasonings to a saucepan and cook on medium heat for 15-20 minutes, until slightly reduced.
Serve the meatballs with the sauce, or any way you like them.
All air fryers have different wattage and may cook at different rates. You may need to adjust the time or temp for the best results.