Turn on the saute function on your Instant Pot and drizzle the olive oil over the bottom.
Season the chicken with salt and pepper and saute on both sides until no longer pink.
Add the garlic, onion, Italian seasoning, peppers and chicken stock and continue to saute a couple more minutes.
Add the tomatoes and close the lid, make sure the steam valve is in the sealed position.
Cook on manual high pressure for 8 minutes.
When the timer goes off release the valve, use an oven mitt or kitchen towel for protection.
Stir and let the sauce sit for a couple minutes.
If you would like to thicken the sauce, in a small bowl mix together 1/4 cup corn starch and 2 tablespoons cold water.
Add to the sauce mixture and stir.
Serve over Fettuccine noodles
*Always check the temperature of your meat cooked in the Instant Pot to make sure it is cooked to a safe temperature.