In a large pot over high heat, add the olive oil. Add the mushrooms and sauté until golden and all the moisture has evaporated, about 10 minutes. Add the meat and continue to cook until browned as well. Add the onions, carrots, and celery and continue to sauté on medium heat until the vegetables are soft, about 5 to 6 more minutes. Add the garlic and cook for one more minute.
Add the wine, stirring to release any of the drippings that are sticking to the bottom of the pan. Allow the mixture to cook for 5 more minutes, or until the wine is mostly evaporated.
Add the tomato paste and stir well. Sauté until the tomato paste has turned a brickish red. Deglaze the pan with the beef stock, add the bay and rosemary, and simmer until reduced and all is tender. Add the beans and cream and continue to cook until it achieves a sauce-like thickness. Remove the rosemary and the bay leaf.
Season with salt, pepper, nutmeg, and parmesan cheese and taste. Adjust the seasonings as needed.
The sauce is ready to add to your cooked pasta, or will store in the refrigerator for up to 4 days.
Bring a large pot of salted water to a rolling boil. Add the pasta and follow package directions until pasta is cooked.
Drain the pasta in a colander and shake well to remove any extra water clinging to the pasta. Pour the pasta in a large serving bowl. Add the sauce and toss together until the pasta is evenly coated.