Step 1In a large Dutch oven or deep skillet, heat the olive oil over high heat. Add the beef, veal and pork and sprinkle with salt. Cook for about 15 minutes, turning occasionally. Add the onion and cook, stirring occasionally, until the onion is golden and the meats are browned on all sides, about 15 minutes more.
Step 2Add the wine and cook until it evaporates, about 10 minutes. Add the tomatoes and chile pepper flakes and simmer, stirring often, for 2 1/2 hours, or until the sauce is thick enough to coat the back of the spoon and the meat is tender.
Step 3Use a slotted spoon to remove the meat from the sauce. Reserve for another dish, serve the meat separately as a second course or chop the meat and return it to the sauce. Season with salt and pepper and toss the pasta with the sauce. Top with grated cheese and pass more cheese at the table.