Bring a large pot of water to a boil for pasta, salt water and cook fettuccine to al dente. Heads up: Compare the cook times on each box to stagger the addition of pastas if necessary to boiling water and reserve 1 cup starchy cooking liquids just before draining.
Meanwhile, heat a large skillet over medium to medium-high heat. Add the butter and melt, add the prosciutto or pancetta and brown 2-3 minutes. Add the sprouts and sauté 3-4 minutes, add garlic or shallot and sage, and toss 2 minutes more. Season with salt, pepper and a little nutmeg.
Drain pasta and add reserved cooking liquid to sprouts. Toss with pasta and cheese, adjust seasonings and serve.