In a mixing bowl, add the sliced chicken thighs, 1 tablespoon of soy sauce, and 1 tablespoon of the sherry. Let it marinate at room temperature for 30 minutes.
Add the remaining soy sauce with cornstarch to a small bowl and whisk to form a slurry. Add the remaining sherry, chicken broth, sesame oil, sugar, and black pepper.
In a small bowl, add the bell peppers and onion. In a separate bowl, add the garlic and ginger.
Add the oil to a non-stick pan or skillet. Once hot, add the chicken and cook for 4-5 minutes, until no longer pink. Remove from the pan.
Add the peppers and onions and stir fry until tender. Add the chicken back, along with the garlic and ginger. Cook for 30 seconds, before adding the sauce mixture and let everything cook together for 2 minutes.
Notes
TO STORE: Place leftovers in an airtight container and store in the refrigerator for up to 3-4 days. TO FREEZE: Place chicken in a shallow container and store it in the freezer for up to 6 months.TO REHEAT: Microwave the chicken for 30-40 seconds or reheat in a non-stick pan.