Easy Bulgogi (Korean BBQ Beef)

Combine yellow onion, white and light green parts of green onions, soy sauce, sugar, sesame seeds, garlic, sesame oil, red pepper flakes, ginger, and black pepper in a bowl until marinade is well mixed. Add steak slices to marinade; cover and refrigerate, 1 hour to 1 day.

Heat a skillet over medium heat. Working in batches, cook and stir steak and marinade together in the hot skillet, adding honey to caramelize the steak, until steak is cooked through, about 5 minutes. Garnish bulgogi with green parts of green onions.