Combine the chicken broth, garlic, salt, and pepper in the inner pot of the Instant Pot.
Layer the fettuccine noodles in the broth in layers, crisscrossing the direction of the noodles for each layer. This will help prevent the noodles from sticking together.
Place cubes of butter over the noodles. Pour in the heavy cream.
Place the lid on the inner pot and be sure the vent knob is sealed. Set to cook on high pressure for 6 minutes by hitting the manual or pressure cook button and use the +/- buttons to adjust until it reads "6."
Once the cooking time has elapsed, allow the pressure to release naturally on its own for exactly 5 minutes. After 5 minutes, use a long wooden spoon to knock the vent knob from the sealed to the venting position. I find that it is best to do a controlled pressure release, which means to slowly turn the vent knob from the sealed to the venting position to release the steam. This will help prevent starchy liquid from spewing out of the venting knob.
Open up the Instant Pot and stir the noodles into the sauce. It is okay that there is extra liquid, the noodles will absorb as they sit. Stir in the parmesan cheese, pop the lid back on the inner pot, and let the fettuccine alfredo sit for a couple of minutes to allow the cheese to melt into the sauce.
Serve with additional parmesan cheese if desired.
Video
Notes
Heavy Cream: Absolutely, NO substitutions. Parmesan: Use good-quality, freshly grated parmesan cheese for the best flavor.Storage: Fettuccine Alfredo is best served immediately after preparation. However, leftovers can be stored in an airtight container for up to 3 days in the refrigerator. You may need to add in a tablespoon or two of broth or cream per serving when reheating the pasta, as the pasta will absorb the sauce as it sits. Adding Chicken:
After pouring the cream into the inner pot, place trimmed chicken tenders or boneless, skinless breasts that have been cut into 2-inch strips on top of the pasta mixture in the inner pot. Sprinkle the chicken with a bit of salt and pepper.
Pressure cook as directed with a 5-minute natural pressure release.
Before stirring in the parmesan cheese, remove the chicken to a cutting board. Dice the chicken into bite-sized pieces and stir back into the pasta, along with the cheese.