Turn the Instant Pot to Sauté mode. Once the display reads HOT, add the oil and ground beef or chicken. Once the meat is almost browned, add the onion and garlic and continue to sauté until the meat is cooked through.
Drain any fat that has collected in the bottom of the pot.
Add the bell pepper, rice, diced tomatoes, tomato sauce, broth, and Worcestershire sauce to the ground meat mixture.
Stir the mixture and loc the lid in place with the valve in the Sealing position. Pressure Cook/Manual on HIGH for 5 minutes.
Once the cooking time expires, allow for the pot to Natural Pressure Release for 5 minutes. Then do a controlled quick release to releases any remaining pressure.
Serve warm and top with shredded cheese as desired.