Marinate Chicken: Rinse the bone in, skin on chicken thighs & drumsticks with water. Pat them dry with kitchen tissues and keep them in a clean, dry bowl. Add the soy sauce, vinegar, black peppercorns, 1 bay leaf (broken into pieces), brown sugar and 5 mashed garlic cloves. Stir well with a spatula to coat the chicken with all these ingredients. Marinate the chicken over night in the fridge or for at least 1 hour. Note: Mix the brown sugar in the soy sauce first & than add it to the chicken.
Sear Chicken: Set Instant Pot on SAUTE function & set it on HIGH heat. Add oil, when the oil becomes hot gently release the marinated chicken (shaking off excess marinade, save the marinade). Sear the chicken both sides very well until golden. Set them aside. Don't worry about the brow bits sticking at the bottom of the pot. We'll be de-glazing the pot later.
De-glaze pot: Now, throw in the remaining 5 mashed cloves of garlic in the pot and saute for just 30 seconds. Pour water and de-glaze the pot with the help of the spatula scraping the sides & the bottom of the pot so that there are no stuck food particles remaining. This is important and will prevent the BURN error. CANCEL the SAUTE function.
Pressure Cook Chicken: Transfer the seared chicken into the pot. Pour the saved marinade all over the chicken. Add the remaining bay leaves. Secure the lid, seal the valve and PRESSURE COOK on HIGH for just 6 minutes. Once, the pressure cooking cycle is over the instant pot will begin to beep, wait for 10 mins Natural pressure release (NPR) than release the rest of the pressure manually by moving the valve from the sealing to the venting position. Open the lid carefully.
Thicken Sauce: Hit SAUTE function and set it on HIGH heat. Fish out the cooked chicken with the help of a pair of tong and set them aside in serving bowl. Simmer the sauce to thicken stirring often. We prefer a flowy sauce which is not too thick. However, you can keep the sauce the way you prefer - thick or thin! CANCEL saute.
Serve Adobo Chicken: Pour the thicken sauce all over the cooked chicken and serve the Instant Pot Adobo chicken with hot steamed rice! You may garnish with fresh chopped red Thai chilies if you prefer spicy food. Enjoy!