Preheat oven to 400 degrees Fahrenheit and line two large rimmed baking sheets with parchment paper.
In a large mixing bowl, combine ground beef, panko, egg, 1 tablespoon soy sauce, half the minced ginger, and half the minced garlic.
Form the beef mixture into 16 evenly sized meatballs and arrange on the first prepared baking sheet.
On the second baking sheet, toss broccoli florets and bell pepper strips with olive oil, salt, and black pepper.
Place both baking sheets in the oven; roast for 18 to 20 minutes until meatballs are cooked through and vegetables are tender-crisp.
In a small saucepan over medium heat, whisk together the remaining soy sauce, sesame oil, brown sugar, gochujang, rice vinegar, remaining ginger, and remaining garlic.
Simmer the sauce for 3 to 5 minutes until thickened into a glaze.
Toss the cooked meatballs in the glaze until fully coated and serve immediately with the roasted vegetables, garnished with sesame seeds and green onions.