Whenever someone asks me what my favourite thing is to cook, this is my answer. I've cooked this countless times since a family friend in Bologna gave us his simple recipe, and I will never get tired of it. I've tried a few recipes from different sources over the years with varying degrees of complexity; some had chicken liver added, many had a mixture of pork, veal and beef, while others required you to render the fat from lardons at the start. For my money, this is the best balance of simple and delicious. For best results, dice all of the vegetables extremely finely (brunoise if you will) and try to break up the meat into the smallest possible pieces while it's browning.