Combine paprika, chili flakes, salt and garlic powder.
Rub the seasoning onto the skin of the chicken.
In the Instant Pot with the sauté function, add 2 tablespoons of olive oil.
Add chicken thighs and cook on each side for 2-3 minutes until the chicken is golden brown. Remove chicken from the Instant Pot and set on a plate.
Add butter to the instant pot. Add the chopped onion and minced garlic. Sauté for a minute. Add the lemon juice and deglaze the pan by scraping the bits off the bottom.
Add Italian seasoning, lemon zest and chicken broth. Stir to combine.
Put the chicken back into the Instant Pot. Put the lid on and lock. Turn the valve to sealing.
Set to cook for 7 minutes. When the pressure cooker is done, allow to naturally release for 5 minutes.
Turn the valve to release and allow all the steam to release. Push stop.
Unlock the lid and remove chicken to a clean plate and set aside.
In a small bowl, whisk together cornstarch and water. Add slurry to the juices in the Instant pot. Turn back to sauté. Whisk and heat until the sauce thickens, about 5 minutes. Put chicken back into the pot, coating with the sauce. Serve.