While the water is heating, slice the pork tenderloin into 1" medallions. Place in a baking dish or baking sheet. Bake the pork for approximately 12-14 minutes until the middle of the pork reads at 150F in temperature. Remove when ready and let rest.
When the water is boiling, add the fettuccine and cook as per package directions until al dente, approximately 10 minutes. When done, drain and set aside.
While the pork and pasta are cooking, make the sauce. Heat the butter in a large skillet over medium heat.
Add the mushrooms and sautee until they start to soften, approximately 3-5 minutes.
Add the garlic to the mushrooms and cook until fragrant, approximately 30 seconds.
Mix the heavy cream into the mushrooms and stir to combine. Reduce the heat to low.
Add the ground black pepper, Parmesan cheese, and 1/2 tsp salt. Add more of each as needed to taste.
Add the cooked pasta into the sauce skillet and stir to combine. Let it cook for 1-2 minutes to incorporate all of the flavors and ingredients. Add additional cream, water, or stock if needed to loosen the sauce.
Serve immediately with the pork medallions. I also love to serve a vegetable to compliment the heavier cream sauce.
Notes
A 1.5 pound tenderloin gave me 12 medallions at 1" wide each. This will vary with the exact shape and size of your pork.Easily double the pasta if desired. As the pasta is heavy, it goes further than a light pasta in portions.It is very important to ensure that your pork is cooked thoroughly to the 150 internal temperature. You pork may reach this temperature slower or faster than 15 minutes.You can use a coarse ground black pepper in place of freshly cracked black peppercorn.