Bring a large pot of water to a boil, salt it, add the pasta and cook until al dente. Drain, reserving 1 cup of the pasta cooking water.
While the pasta is working, in a dutch oven, heat the EVOO, 4 turns of the pan, over medium-high heat. Add the mushrooms and cook, stirring, until browned, about 5 minutes. Add the pancetta and prosciutto and cook until crisp, 2 to 3 minutes. Crumble in the veal (I use a potato masher). Cook until lightly browned. Add the onion, garlic and bay leaf; season with salt, pepper and grated nutmeg. Partially cover and cook until the onion is softened, about 5 minutes.
Stir in the tomato paste for 1 minute. Add the stock, wine and milk; simmer at a rapid bubble, stirring frequently, until thickened, about 10 minutes. Discard the bay leaf.
Add the pasta, reserved pasta cooking water and cheese to the sauce; toss. Serve in shallow bowls.