Mix the coarsely chopped onion, carrot, celery and fennel (optional) together and finely chop them (this is called a battuto in Italian, or a finely chopped mixture of vegetables and herbs to flavour a dish)
Cut the ham or bacon into little cubes and saute in a heavy sauce pan
Add the butter and allow it to melt. Then add the battuto
Cook, stirring occasionally until very lightly browned
Add this mixture to a heavy pot
Heat the olive oil in the skillet the battuto was browned in and when the oil is hot, add the beef and stir to break up lumps, cooking until well browned
Add to the battuto in the pot
Add the wine to the skillet the beef was in and stir on high heat, scraping any brown bits stuck to the pan
Add the tomato paste and stock and stir until well mixed and add this mixture to the pot
Drain and coarsely chop the plum tomatoes and add them to the pot
Add the bay leaf and lemon rind
Bring the pot to a boil, then reduce to a gentle simmer, with bubbles barely breaking the surface
Simmer, stirring occasionally for an hour (or more), until thick
Add pepper to taste, and salt if necessary to taste
When the sauce is ready, bring a gallon (4 litres) of water to a full boil over high heat in a large pot
Add the pasta, give it a brisk stir to ensure it is all covered by water and not clumped together. Cook for about 10-12 minutes, or until al dente (firm but not hard, there should still be a bit of 'bite' when chewing pasta, rather than soggy and mushy)
Drain the pasta well and serve immediately
Remove the bay leaf and lemon rind, then spoon the Bolognese sauce over the pasta and have guests garnish with the grated Parmesan cheese.
This is a great recipe for making in large quantities and freezing. I have made up to 20 times the recipe and frozen in four-cup (1 litre) servings for our family so we can enjoy the pasta sauce over and over without having to start from scratch each time. If making bulk recipes, be sure to simmer for hours, or even a full day, occasionally stirring up from the bottom of the large pot to ensure the contents at the bottom does not burn, adding stock as needed to keep the right consistency. The goal is to have the flavours mix and make the home smell delicious!
Never rinse pasta with water. To ensure there is no excess starch from the pasta, choose a high quality durum wheat pasta and boil it in lots of water.