Marinate the chicken with gochujang, soy sauce, minced garlic, and grated ginger for at least 30 minutes.
Prepare the vegetables by washing and chopping them into bite-sized pieces.
Heat a skillet or wok over medium-high heat, add sesame oil, and cook the marinated chicken for 5-7 minutes until cooked through.
Add the white parts of the green onions and prepared vegetables to the skillet and stir-fry for 3-5 minutes.
Combine the cooked chicken with the vegetables, mixing well, and adjust seasoning if desired.
Garnish with the green parts of the green onions and serve hot over rice or noodles.