Chop the chicken breast into small cubes. In a medium bowl, mix the soy sauce, sugar, sesame oil, ginger, and garlic powder. Place the chicken in the bowl and let it marinate for 30 minutes to an hour.
When the chicken is marinated, heat a skillet with the olive oil over medium-high heat. Once the pan is hot, cook the chicken breasts (about 7-10 minutes, depending on the size of the chicken pieces).
Distribute the cooked chicken, pickled vegetables, cabbage, red pepper, and green onions in the tortillas. Fold it up, and enjoy! If you want some more heat in the tacos, add the red pepper flakes.
Refrigerate any leftovers in an airtight container.
If you don’t like pickled vegetables, feel free to substitute it for some shredded lettuce.