Defrost shrimp (if frozen) in cold water. Then remove shells and tails.
Add chicken broth, garlic, nutmeg, and salt to pot and mix well.
Then add fettuccine noodles, making sure to spread them apart as much as possible. DO NOT STIR!
Then add cream, making sure that all noodles are submerged. AGAIN… DO NOT STIR!!
Lock lid and cook for 2 minutes at high pressure. Once cook time is complete, allow pressure to release naturally for 5 minutes. Then quick-release remaining pressure. (If starchy bubbles try to escape the vent, simply close the vent for 30 seconds or so, then release again in intervals.)
Meanwhile, using a microplane, grate Parmigiano-Reggiano cheese.
Mix pasta and sauce well, making sure to break up any noodles that may be stuck together. Add all cheese to the pot and mix well.
Finally, add shrimp to pot and mix, making sure to submerge all shrimp. Return lid to pot and let sit for about 10 minutes. The shrimp will cook in the residual heat, and the sauce will thicken the longer it sits.
Serve topped with cracked black pepper (and maybe more cheese).