In a large mixing bowl add meat, panko, corn starch, scallions, egg, ginger, garlic, sesame oil, salt, and pepper. Using your hands, mix until thoroughly combined. Cover bowl with plastic wrap and refrigerate for at least 15 minutes, up to overnight. Using wet hands, form mixture into 1 1/2-inch long slightly oval meatballs (like tiny meatloaves). Thread 2 to 3 meatballs onto each skewer (if grilling). If broiling, place balls on a lightly greased foil-lined baking sheet).