Blend basil, cashews, parmesan, garlic, ½ teaspoon salt, and 2 tablespoon olive into a smooth paste and keep aside.
Add salt and pepper onto the chicken pieces and spread the prepared pesto on top of the chicken. Mix properly.
Set the instant pot on SAUTE function, let it heat up.
Add 1 tablespoon oil; next, add in the pesto coated chicken pieces, sauté it for a few minutes until the chicken changes color.
Take it out and set it aside. CANCEL the SAUTE button.
Add 1 tablespoon of chicken stock and deglaze the pot properly.
Next, add the chicken pieces, cherry tomatoes, and leftover chicken stock.
Close the lid and pressure valve. Select the PRESSURE COOK button on HIGH PRESSURE and cook for 6 minutes.
Once the pressure-cooking cycle is over, quickly release the pressure by manually moving the valve from SEALING to VENTING position.
Open the lid carefully and select the CANCEL button.
Serve the hot chicken pesto over cooked spaghetti or pasta with shredded mozzarella on top, garnish with cherry tomatoes.
Plate, serve, and enjoy!