Cook the Pasta: Bring a large pot of generously salted water to a boil. Cook the fettuccine according to package directions until al dente. Before draining, carefully reserve 1/2 cup of the starchy pasta cooking water. Drain the pasta and set aside.

Brown the Butter & Fry the Sage: While the pasta cooks, melt the butter in a large, light colored skillet over medium heat. Cook, swirling the pan occasionally, until the butter foams, then turns a deep amber color and smells nutty (about 3-5 minutes). Add the sage leaves and fry for 30-60 seconds until crisp. Immediately remove the sage leaves to a paper towel lined plate.

Make the Sauce: To the brown butter in the skillet, add the veal stock (or broth substitute). Let it simmer for 30 seconds to combine.

Combine: Add the drained hot pasta and 5 tablespoons of grated Parmigiano cheese to the skillet. Using tongs, toss vigorously over low heat until the cheese melts and the pasta is evenly coated. Add the reserved pasta water, one tablespoon at a time, until the sauce is silky and clings to the pasta.

Season & Serve: Season the pasta with freshly ground black pepper and a pinch of salt to taste. Divide among bowls, garnish with the crispy fried sage leaves, and serve immediately with extra grated cheese on the side.