Preheat oven to 400°F and coat a baking sheet pan with avocado oil cooking spray. Mix all meatball ingredients until just combined. Add more almond flour if needed.
Form into golf ball-sized meatballs and place on the sheet. Bake 18-22 minutes, or until meatballs are cooked through and nicely browned on the outside.
Meanwhile, whisk sauce ingredients (except arrowroot) in a saucepan over medium heat. Stir in dissolved arrowroot; cook until thick and glossy. Add sweetener if desired.
Toss hot meatballs in the sauce until coated. Garnish with green onions and sesame seeds. Serve warm.
