Set Instant Pot to saute mode and add olive oil.
Once oil is hot, mix in onion, bell pepper, and ground beef. Cook, stirring occasionally, until beef is browned. About 5 minutes.
Mix in garlic and salt and pepper (to taste) and saute for another 30 seconds, until garlic is fragrant.
Turn off instant pot.
Add in diced tomatoes, tomato paste, parsley, oregano, basil, and bay leaf. Mix and scrape up any bits off the bottom of the instant pot.
Then pour in the elbow macaroni and top with marinara and water. Do not stir.
Close lid on instant pot and set to sealing. Cook on manual - high pressure, for 5 minutes.
Do a controlled quick pressure release (Let the steam out in bursts).
Mix and serve immediately, topped with sharp cheddar.