Heat Instant Pot on Sauté mode. Add butter and drizzle enough olive oil to lightly coat bottom of pot.
Add chopped chicken breasts, onion, garlic, and mushrooms to the Instant Pot. Sauté chicken mixture for 5 minutes. When you start to see color on the chicken pieces, add frozen peas and carrots.
Sprinkle flour over top of chicken mixture. Gently stir to