Add your onions, garlic and alfredo sauce into your pot, stir until combined. If you like your shrimp on the well done side add those in now too. (we did, you can see in the photos)
Pour in your water or broth and stir until smooth. Add peeled jumbo shrimp on top now. If you're using really tiny shrimp wait to add those until later.
Pour in your uncooked noodles and submerge into the liquid.
Close lid and steam valve and set to high pressure for 3 minutes. (if you like your small noodles to be more al dente, set for 2 min.)
Quick release. If you have very small shrimp just add them to the top of your done alfredo inside your pot now and close the lid back up for 5 mintues to steam them. Then add grated romano and parmesan cheeses and stir so they melt. Serve!