Finely chop chicken breast, onion, green onion, perilla leaves, and chili pepper.
Heat oil in a pan and stir-fry the chicken breast.
Add onion, green onion, and chili pepper, and stir-fry together.
Add dakgalbi sauce and mix well with the other ingredients while stir-frying.
Add brown rice and continue to stir-fry until the ingredients and sauce are well combined.
Top with perilla leaves, stir-fry once more, and serve.