Preheat the oven to 400 degrees F and line a large baking sheet with parchment paper.
In a mixing bowl, combine the ground beef, gochujang, panko breadcrumbs, egg, minced garlic, grated ginger, soy sauce, and black pepper. Mix until evenly combined, then shape the mixture into 8 small oval meatloaves.
Place the meatloaves on one side of the prepared baking sheet. In the same mixing bowl, toss the chopped Napa cabbage and carrot rounds with the sesame oil until coated. Spread the vegetables on the other side of the baking sheet.
Bake for 20 to 25 minutes, until the meatloaves reach an internal temperature of 160 degrees F and the vegetables are tender. Remove from the oven and sprinkle the sliced green onions over the top before serving.