Place 2 boneless chicken breasts, 4 peeled and diced carrots, ½ chopped onion, 1 (15-ounce) can diced tomatoes, 1 diced red bell pepper, 2 tablespoons Italian seasoning, 1 teaspoon garlic salt, 1 bay leaf, 1 teaspoon black pepper, ½ teaspoon salt, and 8 cups chicken broth into the Instant Pot.
Secure the lid and make sure the pressure release valve is set to the Sealing position.
Cook on High Pressure for 25 minutes. When the cook time is complete, carefully perform a quick release to release the pressure.
Remove the chicken breasts from the Instant Pot and shred them with two forks. Return the shredded chicken to the Instant Pot and discard the bay leaf.
Stir in 16 ounces uncooked rotini pasta.
Turn the Instant Pot to the Sauté setting and bring the soup to a boil. Cook for 8-10 minutes, stirring frequently, until the pasta is tender.
Switch the Instant Pot to the Keep Warm setting and stir well to combine.
Serve the soup warm, topped with ¼ cup shredded Parmesan cheese.
Notes
Refrigerate the leftovers in an air tight container for up to 5-7 days.