Bring a large pot of water to a boil for the pasta.
In a large skillet, melt the butter over medium to medium-high heat. When it bubbles and foams, add the sage leaves and cook, stirring often, until the sage is crisp and the butter browns, about 2 minutes. Using a fork, transfer the sage to a paper towel to drain.
Add the meat to the butter and cook, breaking the meat up with a wooden spoon, until browned, 3 to 4 minutes. Add the onion and garlic; season with salt, white pepper, and nutmeg. Cook, stirring occasionally, until the onion softens, about 5 minutes. Add the wine and cook, stirring occasionally, until evaporated, about 2 minutes. Add the stock, milk, and Parm rind and simmer until the sauce thickens, 12 to 15 minutes. Discard the rind.
Salt the boiling water and add the pasta. Cook until 1 to 2 minutes shy of the package directions. Reserve 1/2 cup of the cooking water, then drain. Toss the pasta, cooking water, and grated cheese with the sauce until the pasta is generously coated, about 1 minute. Serve in shallow bowls and top with the crispy sage.