From http://cooking.nytimes.com/recipes/1015181-marcella-hazans-bolognese-sauce
75 g onion
100 g carrots
65 g celery
340 g ground beef
2.3 dl milk
2.3 dl white wine
3.5 dl canned imported Italian plum tomatoes, cut up, with their juice
1 tablespoon oil
3 tablespoons butter