Sauté Onion: Turn on Sauté and adjust the heat level to Normal. Allow the pot to heat up until the display reads Hot. Add the olive oil and allow it to heat up. Add the diced onions to the pot and toss until thoroughly coated in the oil. Sauté, tossing occasionally, until they become soft and translucent. About 3 to 4 minutes.

Add the minced garlic to the pot and continue to sauté for another 30 seconds. Deglaze the pot with the white wine vinegar and cook until it almost completely evaporates. About 1 or 2 minutes.

Add the Italian sausage to the pot and cook, breaking it apart into smaller and smaller pieces as it cooks. Continue for 4 minutes. Add the salt and pepper and mix into the sausage. Continue cooking until cooked through, about another 2 or 3 minutes.

Add the bell pepper and mix into the sausage. Cook for another minute or two, tossing occasionally. Turn off Sauté.

Add Rigatoni: Add the water to the pot and deglaze the bottom of the pot once more. Then layer the rigatoni pasta over the sausage and push it down into the water as much as you can. Pour the marinara sauce evenly over the top of the pasta. Do not mix.

Close the Instant Pot, set the pressure release valve to Sealing and set the pot to cook on Manual or Pressure Cook, High Pressure for 7 minutes.

2-Minute NPR: Once the 7-minute cook time has completed, allow for a 2-minute Natural Pressure Release. When the 2-minute NPR has finished, release the remaining pressure and then open the pot.

Add the heavy whipping cream and parmesan cheese to the pot and mix them into the pasta. Allow the pasta to sit on Keep Warm for 5 to 10 minutes to allow the sauce to thicken.