Peel and cut onion in half and add to cooking pot.
Pour in pureed tomatoes, water, cream and wine (or water/broth).
Add butter, Italian seasoning, garlic, salt, pepper and pepper flakes and mix through.
Add Ziti noodles.
Lock on lid and close pressure valve. Cook at high pressure for 2 minutes.
When beep sounds, wait 3 minutes and then remove the rest of the pressure.
Remove lid and retrieve the onion.
Hit the sauté/browning button and slowly add in Mozzarella and Parmesan cheese. Wait for the cheese to start to melt and then mix it in.
Mix in Ricotta cheese and add fresh parsley if desired.
If you want to skip the red wine (but why would you????) replace it with water.Evaporated milk can be used in place of heavy cream.If you like a creamier ziti, add a bit more cream and subtract that amount of water.
How to add Cheese to Instant Pot Baked Ziti
Add a handful at a time and allow the cheese to melt on top and then mix it in.
his will help prevent the cheese from accumulating on the sides and bottom of the pot.