Cut the chicken breast into strips. Place the strips in a non-metallic bowl or a Ziploc bag.
Combine the gochujang paste, soy sauce, apricot jam, sesame oil, gochugaru, fish sauce, and rice vinegar.
Marinate: Pour the marinade over the chicken and mix well. Marinade for at least 30 minutes or up to 6 hours.
Bring the chicken to room temperature before cooking, about 30 minutes on the counter should be fine.
Finely slice the green onions. Set aside.
Cook the gochujang chicken strips in two batches.
Heat ½ of the oil in a large nonstick pan or cast-iron skillet. Place ½ of the chicken strips in the pan. Cook for 2 minutes without moving. Flip the chicken and cook for another minute or until cooked through. Remove from the pan.
Pour the remaining oil into the pan and cook the second batch of chicken strips. Return the first batch of chicken to the pan.
Add ⅔ of the sliced green onions to the pan. Stir fry for 1 minute.
Sprinkle the gochujang chicken with the remaining green onions and the sesame seeds.
Notes
Use gochujang paste and gochugaru (red pepper flakes) according to taste/heat tolerance. Gochujang paste can be mild, medium, or very hot, adjust the quantity accordingly.