For the meat loaves, in a large bowl combine oats, onion, coconut aminos, and pepper. Add beef; mix well. Shape meat mixture into 8 patties, each about ¾-inch-thick. For the sauce, stir together tomato paste, coconut aminos, honey, vinegar, water, and, if desired, ginger. If desired, transfer 1 to 2 tablespoons of the sauce to a separate bowl for brushing on the meat loaves after they are finished grilling.