In your Instant pot, combine garlic, chicken stock, oregano, basil, red pepper and chicken.
Cook on high pressure for 10 minutes. When done, do a quick pressure release.
Using tongs, carefully remove the chicken to a platter to let rest while you prepare the sauce.
Select "saute" on Instant Pot, and let simmer, stirring occasionally for 7-10 minutes until the sauce reduces by about 1/3.
Add half and half, stir in the parmesan cheese, and add lemon juice. Stir until cheese is melted and sauce is heated through, do not let it boil.
OPTIONAL: Make a slurry with the cornstarch and water, add to simmering sauce and stir until thick and creamy.
Spoon sauce over chicken and serve. I will be serving it over rice.