Whisk together the broth, roasted red peppers, pesto, garlic, Italian seasoning, salt and pepper. Set aside.
(OPTIONAL) Turn the Instant Pot to saute. When it reads 'hot', drizzle oil in the bottom. Sear the chicken breasts on each side for 2 minutes until light golden brown. This step is optional but does add flavor. Be careful not to overcook!
Place the chicken on the trivet (again, optional! You can also cook it right in the sauce) and add the sauce.
Place lid on the Instant Pot and turn valve to sealing. Select Manual, high pressure (the default), and set the timer to 6 minutes. The pressure cooker will take about 10 minutes to build pressure and begin counting down. *If you did not sear the chicken, add 2-3 minutes. For frozen chicken, add 4-5 minutes.
Once the cook time is over, turn the Instant Pot off and let pressure release naturally for 10 minutes, then do a quick release and open the lid.
Remove the chicken breasts and place on a cutting board or serving platter. Turn the Instant Pot to saute. (OPTIONAL: strain the broth if there is fat left over)
Stir together cream and corn starch and add to the pot. Whisk and cook for 3-4 minutes, until thickened. Add chicken back to the sauce or serve with the sauce over top if desired.
