How to Make It
Preheat grill to medium-high (400°F to 450°F); or heat a grill pan over medium-high, and lightly grease. Stir together egg, ginger, garlic, salt, pepper, and 1 tablespoon of the gochujang sauce in a large bowl. Add pork and panko, and gently mix with hands until just combined. Form into 24 (1 1⁄4-inch) meatballs (about 1 ounce each). Thread meatballs, alternating with scallion pieces, onto 8 (8-inch) skewers.
Place kebabs on lightly greased grill grate or in grill pan. Grill, uncovered, until meatballs are lightly charred and cooked through, 12 to 14 minutes, turning occasionally.
Whisk together soy sauce, vinegar, oil, sugar, and remaining 3 tablespoons gochujang sauce in a small bowl. Place each skewer on a lettuce leaf, and spoon 2 teaspoons sauce over each kebab. Sprinkle with peanuts and cilantro. Serve with lime wedges and remaining sauce.