Season the chicken thighs with salt and pepper.
On the Instant Pot, press on SAUTE, add the oil and melt the butter. Brown the chicken starting skin side down, flip and brown it from the other side. When the chicken is golden brown, remove from the pot and set aside.
Melt the remaining butter in the Instant Pot, and add the garlic. Cook for a minute until it's fragrant.
Add the chicken stock, and deglaze scraping off any stuck bits to the bottom of the pot.
Add the honey, brown sugar, oregano, basil, and thyme. Season with a pinch of salt, and put the chicken back in the pot.
Secure the lid and set the vent to SEALING. Select the PRESSURE COOK/MANUAL setting and set the cooking time for 8 minutes at high pressure. The Instant Pot will take around 6-7 minutes to come to pressure and start cooking. When the cooking program ends, quickly release the steam.
Transfer chicken thighs to a serving plate, and to thicken the sauce (optional), set the Instant Pot to SAUTE mode, and add 1 tablespoon of cornstarch mixed with 1 tablespoon of water. Add that to the sauce, and whisk until the sauce thickens. Have a taste and add more salt if needed.
Pour the sauce over the chicken, and garnish with chopped parsley leaves.