Best Instant Pot® Chicken Cacciatore
1 (8 ounce) package sliced fresh mushrooms 1 green bell pepper, diced 1 pound skinless, boneless chicken thighs 1 red bell pepper, diced 1 small onion, chopped 1 tablespoon fresh ground black pepper 1 tablespoon sea salt 1 ½ teaspoons red pepper flakes, or to taste 2 large jarred roasted red bell peppers, chop… 2 small skinless, boneless chicken breasts, h… 2 teaspoons chicken bouillon granules 2 teaspoons garlic powder 2 teaspoons Italian seasoning 2 teaspoons onion powder 3 stalks celery, chopped 3 tablespoons extra-virgin olive oil, divided 3 tablespoons tomato paste 4 cloves garlic, minced ¼ tablespoon cornstarch ¾ cup dry Cabernet Sauvignon