01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large bowl, combine ground beef, minced garlic, chopped green onions, egg, soy sauce, panko breadcrumbs, sesame oil, gochujang, brown sugar, grated ginger, black pepper, and salt. Mix until just combined—do not overmix.
03 - Shape the mixture into 20 to 24 bite-sized meatballs, about 1 tablespoon each. Arrange on the prepared baking sheet, spacing evenly.
04 - Bake for 20 to 25 minutes, turning once halfway through cooking, until browned and cooked through to an internal temperature of 160°F.
05 - While the meatballs bake, whisk together mayonnaise, sriracha, lime juice, sesame oil, honey, and salt in a small bowl until smooth. Adjust sriracha to taste for desired heat level.
06 - Transfer cooked meatballs to a serving platter. Sprinkle generously with toasted sesame seeds and sliced green onions. Serve hot with the spicy mayo dip on the side.