A soffrito of finely chopped onions, celery, carrots, and pancetta has been cooked in olive oil.
Meats (beef, pork, and lamb) have been added, lightly cooked until they lose their color, and then are boiled rapidly with milk until the milk evaporates.
White wine has been added and also boiled until it evaporates.
Canned tomatoes and canned, unflavored tomato sauce have been added and are ready to begin cooking, along with a little red wine.
Near the end of the very slow, 8-hour simmering; a little additional water has been added every half-hour or so.
The finished Bolognese, ready to be served on tagliatelle.