So many variations. All intensely satisfying. Time consuming: yes. Difficult: I don't think so.
Onion, carrot, celery
Skirt steak, chicken thighs
Tomato paste, garlic
Wine (white, red, or both)
1. Chop up two or three strips of bacon and sauté to render out the fat, 5 minutes or so. Remove bacon with slotted spoon, leaving fat in the pan. While that's happening:
2. Finely dice an onion, a stalk of celery and a carrot. Saute these in the bacon fat over medium heat-- lowering it as they give up their water-- for about 10 minutes. Remove from pan. While that's happening:
3. Take your pound, pound and a half, of skirt steak and chop it as finely as possible. Cut the meat into matchsticks first, then line a few of them up and cut them across into a dice of about 1/4 inch. Do the same with two chicken thighs. (Or substitute some veal, or some pork shoulder or belly.) Salt and pepper the meat, then:
4. In same pan, add 3 tbls of olive oil and add the chopped meat and sauté until cooked through, about 3 minutes.
5. Add two tbls of tomato paste and stir it around the meat, cooking for about 1 minute.
6. Add 1/2 cup wine to pan and let it sizzle up, give up steam. Stir it until it evaporates, about 2 minutes.
7. Add 1/2 cup milk to the pan and do same.
8. Add a couple of finely chopped garlic cloves, a bit more salt and some freshly ground black pepper, and if you have it, a fine scraping of nutmeg-- but very, very little. Put the cooked bacon and vegetables back in.
9. I add more tomato here-- a can of good tomatoes, or, as I had some in the freezer, some homemade tomato sauce. About two cups. Let it cook down.
10. Start adding stock by the ladleful. I used chicken. But any would work. Also water would work.
11. Keep cooking, simmering, allowing the liquid to evaporate, building it back up. It'll thicken and richen. After about an hour, you'll have a thick, meaty delicious sauce.
Some people will finish this with a little heavy cream. I don't think it needs it. But a tablespoon or two of butter is nice.
Put this on fresh tagliatelle or papparadelle pasta. You don't need a lot. Fresh Parmesan is a must.