Step 1: Marinate the chicken legs with the above seasoning for a few hours, or preferably overnight in the refrigerator. Take them out at least an hour before cooking.
Step 2: Heat up a grill pan with a little bit of oil and once the pan is red hot, add in the chicken pieces, reduce the heat to maintain the temperature, and let the chicken cook for a few minutes.
Step 3: Leave any marinade in the bowl for later use. Once the edges of the meat start to brown, then flip over to the other side and grill for a further few minutes.
Step 4: Dish up onto serving plates. In another pan, heat up some oil and toss in the onion slices and capsicums, stir-fry and dish out.
Step 5: In the same pan, put in the chicken marinade, add in the ground black pepper, oyster sauce and water, let it simmer.
Step 6: Fine tune to taste and add in the thickening. Arrange the onions and capsicums onto the serving plates with the chicken pieces and pour over the sauce.
Step 7: Serve immediately and enjoy.