Add onions, garlic and red pepper flakes. Mix well and cook for 2 minutes with a glass lid on.
Add vodka, mix well and cook for another 2 minutes to reduce down the vodka.
Add pasta, water, and salt. Stir well, making sure to push most of the pasta under the liquids. Layer over the tomato puree or sauce and DO NOT mix. Close the Instant Pot and pressure cook for 4 minutes followed by Quick Release.
Stir in cream. Add parsley and grated cheese. Mix well and serve hot.
Liquids: Add enough water/broth/tomato sauce so that most of the pasta is under the liquids. Depending on the shape of the pasta you may need more or fewer liquids.
Tomato Sauce: Layer the marinara sauce on top of the pasta and do not mix it in
Pasta Cook Times: For a well-cooked pasta, pressure cook pasta for half the time on the pasta box. For Al dente pasta, pressure cook for half the time on the pasta box minus 1 minute. This method also works well for gluten-free brown rice pasta.
Cream: Always add cream after the pasta is done pressure cooking