Mix together marinade ingredients (soy sauce, salt, pepper, oyster sauce, and cornstarch).Pour over chicken and massage into meat. Marinate for 10 minutes. Before cooking, line a baking sheet or large pan with paper towels. This is where you'll place the chicken after cooking it up.
Heat 2 tablespoons of oil in a large skillet, on medium-high heat.
Add chicken and sear until crispy, turning pieces over in pan with tongs as needed to cook sides evenly.
Once pan of chicken is cooked, remove pieces with tongs and place onto prepared paper towels, to absorb some of the oil.
Reduce heat to medium as oil is now hotter, and continue cooking batches of chicken until all the chicken is cooked.Add 1-2 tablespoons more of oil as needed. Once completed cooking the chicken, set it aside and let it rest while you prepare the garlic oil sauce.