Asian Meatballs with Sesame Lime Dipping Sauce

Put oven rack in middle position and preheat oven to 500 °F. Pour milk over bread crumbs in a large bowl and stir until liquid is absorbed. Add ground meat, egg, water chestnuts, salt, chopped cilantro, 1 tablespoon soy sauce, and 2 teaspoons oil and mix with your hands until combined well. Shape 3 tablespoons meat mixture into a ball and transfer to a 13- by 9-inch glass baking dish. Make more meatballs with remaining mixture, arranging meatballs about 1/2 inch apart in baking dish. Bake until cooked through, about 15 minutes. Meanwhile, stir together lime juice, water, sugar, remaining 4 tablespoons soy sauce, and remaining 2 teaspoons oil in a bowl until sugar is dissolved. Transfer meatballs to a serving dish. Stir sauce, then drizzle meatballs with 1 tablespoon sauce and sprinkle with cilantro sprigs. Serve meatballs with remaining sauce.