Step 1

Add 1 1/2 cups of water to the bottom of the instant pot.

Step 2

Add some sauce to the bottom of a dish that is safe to use in the Instant Pot. I use a corningware bowl, but you could also use a silicone baking dish, cake pan, or springform pan.

Step 3

Layer the shells in the dish, then top with some sauce, then add any remaining shells on top, and top with some more sauce. Spread the sauce over the shells so that the shells are 'wet' with sauce all over.

Step 4

Loosely cover the dish with foil, then place on a removable rack, and lower the rack with dish into the Instant Pot. Place the cover on the instant pot and make sure the pressure valve is in the sealed position. Set the Instant Pot to high or manual cook mode, and then set the timer on 15 minutes.

Step 5

When the time is up, move the pressure valve to the side to release the pressure. Careful because steam will come out of the pressure valve. When all the pressure is released, remove the lid. Carefully remove the rack with the dish, then remove the foil (careful).

Step 6

Serve the shells topped with parmesan cheese if desired.