Prepare your air fryer basket by lightly greasing the basket with cooking oil (or cooking spray).
Mix together all the Meatball ingredients. Roll the ground meat into meatballs of about 1 inch to 1½ inch diameter. This should make 12-16 meatballs.
Preheat the air fryer to 375°F for a minute or so. Then air fry the meatballs for about 8 minutes. I usually flip/turn the meatballs and then air fry for about another 5 minutes for a more even browning. If using a meat thermometer, the temperature should reach at least 160°F.
While the meatballs are in the air fryer, make the gravy! In a small sauce pan over medium heat, melt the butter.
Add the onions and cook until soft (about 5 minutes). To get a darker colored gravy, cook the onion until it's caramelized.
Stir in the flour and cook for 1 minute.
Slowly stir in broth and soy sauce until the mixture thickens to your desired consistency, about 3 minutes. Add salt & pepper to taste.
Pour the gravy over the meatballs before serving. Serve & enjoy!