Marinate chicken thighs: Rinse the chicken thighs and pat them dry completely with the help of kitchen tissues. Add all the ingredients mentioned above in the "Chicken Thighs Rub" in a bowl/plate. Place the chicken thighs and coat them well with this dry rub on all sides. Marinate the chicken either over night or for at least 30 mins.
Marinate vegetables: Dice the carrots and onion. Add them in a bowl along with the baby potatoes & garlic. Than, add all the ingredients mentioned above in the "Vegetables Rub" section into the bowl. Coat the vegetables very well with this rub. Set them aside while you sear the chicken.
Sear Chicken: Set Instant Pot on SAUTE function and keep it on HIGH heat setting. Add olive oil & butter and when they become moderately hot gently release the chicken thighs and sear them until golden brown or the skin becomes crispy. Flip sides and sear well, There will be lots of brown bits sticking at the bottom of the pot. Do not worry we'll be de-glazing the pot later. Set aside the seared chicken.
De-glaze pot: Pour the chicken stock and de-glaze the pot very well scraping the bottom & the sides of the pot with the help of a spatula. There should not be any stuck food particles at the bottom of the pot. This will prevent the BURN error! Add the lemon zest. CANCEL the SAUTE function.
Layer veggies & chicken: Now, add the marinated vegetables into the pot. DO NOT mix or stir. Gently spread out the vegetables with the help of a spatula to form a single layer. Transfer back the seared chicken thighs into the pot and place them on top of the veggies in a single layer. DO NOT mix or stir.
Pressure Cook chicken & veggies: Secure the lid of the instant pot, seal the valve and PRESSURE COOK on HIGH for 8 mins. Once, the cooking cycle is over the instant pot will begin to beep. Wait for 5 mins natural pressure release & than release the rest of the pressure manually by moving the valve from the sealing to the venting position. Open the lid carefully.
Sear/broil chicken thighs (OPTONAL): If you prefer crispy chicken than sear the cooked chicken thighs (skin side down) on a cast iron skillet over medium high heat. You may even broil the chicken on the op rack of the oven for 2-3 mins or until the skin becomes crispy. This step is totally OPTIONAL. You can serve the chicken thighs directly after pressure cooking them.
Serve: Serve the instant pot chicken thighs and vegetables on a plate, drizzle or pour the flavored stock from the instant pot, garnish with fresh chopped parsley. Enjoy!.