MARCELLA HAZAN'S BOLOGNESE SAUCE

Put oil, 3 tablespoons butter and chopped onion in a heavy 3-1/2-quart pot and turn heat to medium. Cook and stir onion until it has become translucent, then add chopped celery and carrot. Cook for about 2 minutes, stirring vegetables to coat well. 2. Add ground beef, a large pinch of salt and a few grindings of pepper. Crumble meat with a fork, stir well and cook until beef has lost its raw, red color. 3. Add milk and let simmer gently, stirring frequently, until it has bubbled away completely. Add a tiny grating, about 1/8 teaspoon, fresh nutmeg and stir. 4. Add wine and let it simmer until it has evaporated. Add tomatoes and stir thoroughly to coat all ingredients well. When tomatoes begin to bubble, turn heat down so that sauce cooks at the laziest of simmers, with just an intermittent bubble breaking through the surface. 5. Cook, uncovered, for 3 hours or more, stirring from time to time. While sauce is cooking, you are likely to find that it will begin to dry out and the fat will separate from the meat. To keep it from sticking, add 1/2 cup water as necessary. At the end of cooking, however, the water should be completely evaporated and the fat should separate from the sauce. Taste and correct for salt. 6. Add remaining tablespoon butter to the hot pasta and toss with the sauce. Serve with freshly grated Parmesan on the side.