Set the instant pot to the sauté setting and cook the kielbasa and onion in oil for 3 minutes, stirring occasionally.
Add the green pepper, garlic cloves, cayenne pepper, black pepper, diced tomatoes, frozen shrimp, salt, and 1 cup of water.
Turn the pressure valve to sealing and set manual pressure on high for 6 minutes and then do a quick release.
Mix together the cornstarch and 3 tablespoons of water until smooth.
Set the pressure cooker back to the sauté setting. Pour the cornstarch mixture into the pot and stir to thicken.
Turn the instant pot off and then serve warm and enjoy!