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, being careful not to overmix.
03 - Shape the mixture into 20-24 bite-sized meatballs, approximately 1 inch in diameter. Arrange on the prepared baking sheet, spacing evenly.
04 - Bake for 20-25 minutes, turning once halfway through cooking, until meatballs are browned on all sides and cooked through to an internal temperature of 165°F.
05 - While meatballs bake, whisk together mayonnaise, sriracha, lime juice, sesame oil, honey, and salt in a small bowl until smooth and well combined. Adjust sriracha amount 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 immediately with spicy mayo dip on the side.