Turn the Instant Pot to the ‘Sauté’ mode and heat 1 tablespoon olive oil until shimmering.
Season the chicken pieces with 1 teaspoon salt, 1/2 teaspoon black pepper, 1 teaspoon smoked paprika, and 1/2 teaspoon garlic powder.
Add the seasoned chicken to the Instant Pot and sauté for 3-4 minutes until lightly browned but not fully cooked. Remove the chicken and set aside.
Add the sliced onion, red bell pepper, green bell pepper, and yellow bell pepper to the Instant Pot. Sauté for 3-4 minutes until they start to soften.
Add the minced garlic and sauté for an additional 30 seconds until fragrant.
Return the chicken to the Instant Pot with the vegetables.
Pour in 1/2 cup chicken broth and 1/4 cup tomato sauce. Stir in 1 teaspoon dried oregano and 1/2 teaspoon crushed red pepper flakes.
Secure the Instant Pot lid and set the valve to ‘Sealing’. Cook on ‘Manual’ or ‘Pressure Cook’ high pressure for 8 minutes.
When cooking is complete, allow a natural pressure release for 5 minutes, then carefully perform a quick release to release any remaining pressure.
Open the lid and stir the chicken and peppers. Adjust seasoning with additional salt and pepper if desired.
Serve hot over rice, pasta, or enjoy as is.