In a large, heavy skillet, heat the olive oil until just starting to smoke. Add the onions and saute over medium high heat about 5-8 minutes. Lower the heat to medium and add the garlic, celery and carrot. Sauce for about 5 minutes. Increase the heat to high and deglaze the pan with the wine, scraping up all the bits for about 3-5 minutes or until wine is just about all cooked out. Add the beef, pork and ham or bacon and saute, stirring frequently, breaking up any large lumps and cook until meat is no longer pink, about 10 minutes. Add the tomato sauce, tomato paste and parsley. Cook over medium heat for a few minutes to allow it to thick up a bit. Season with nutmeg, salt and pepper to taste. Add the stock, bring to a simmer, lower heat, cover and cook for about 30 minutes. Add the cream and cook just to warm the cream. Serve over pasta, thinning out with a bit of pasta water if needed. Top with cheese.