Add all ingredients for the meatballs to a mixing bowl and use your hands to mix everything together until well-combined (note: you can also perform this step using a stand mixer with the paddle attachment).
Form meatballs 1.5 to 2 inches in diameter and place on a plate.
Heat 2 tablespoons avocado oil or cooking oil of choice in a large cast-iron skillet over medium-high heat. Once hot, place the meatballs in the hot skillet, giving each one plenty of room (you’ll need to do this in 2 to 3 batches). Cook 2 minutes, flip to the other side and cook another 2 to 3 minutes until browned on 2 sides. Transfer to a plate.
Wipe out the skillet, lower the heat to medium-low and add the sauce. Bring sauce to a gentle boil then add the meatballs and stir. Cover and cook until meatballs are cooked through, about 5 to 8 minutes. For more developed flavor, cook meatballs at a very gentle simmer over medium-low heat for 30 to 60 minutes, stirring occasionally.