In a large bowl, combine the ground meat, water chestnuts, scallions, soy sauce, and sesame oil.
Use a fork to stir the ground meat mixture until its well-mixed. Use your hands to shape the meat mixture into tiny meatballs (1 to 1 1/2 in. diameter).
Heat the vegetable oil in a large skillet over medium heat. Add the meatballs and cook, stirring often, until browned on all sides, about 1 min. Cover and cook until meatballs are no longer raw in the center, about 2 minutes longer.
Meanwhile, in a large bowl, combine the rice, sesame seeds, scallions. Toss well to combine. Serve the meatballs beside or over rice.