Add turkey through ground pepper to a large bowl and mix well with your hands or a wooden spoon.
Divide the mixture into 8-10 meatballs. Place on a large plate or baking sheet.
Heat the olive oil in a heavy, large frying pan over medium-high heat. Add the meatballs – being sure they have space between them, otherwise they will steam – you want a little crust on them for flavor. Sauté until browned on all sides, about 2:30-3 minutes per side. Turn off heat.
Transfer the meatballs to a plate. Pour off any excess oil. Add the marinara sauce.
Return all the meatballs to the pan and cover. Turn the heat to medium-low and simmer until the sauce thickens slightly and the meatballs are cooked to 160 degrees F – approx. 5-7 minutes.
Season the sauce, to taste, with salt and pepper.
Serve over zucchini/squash noodles or cauliflower rice.