Add the bacon to a large deep pot then turn the heat to medium. Fry until crisp with the fat rendered down, then remove and place to one side, leaving the excess fat behind. Add the onion to the leftover fat and fry until soft and golden (top up with a dash of oil if needed). Add the garlic and fry for another 30 seconds or so.
Increase the heat slightly to medium-high then add the beef and fry until browned all over, breaking it up with your wooden spoon as you go. Stir in the tomato paste and fry for a minute or so, then pour in the wine. Simmer for 3-4 minutes to allow the beef to soak up the wine and burn off the alcohol (the pungent alcohol smell should mellow out).
Pour in the passata and shake out the jar with a splash of water (I do 1/4 cup). Stir in the beef stock, bacon, sun dried tomatoes, basil, rosemary, Worcestershire sauce, sugar, salt and pepper then bring to a simmer. Pop on the lid, reduce the heat to low and simmer for 1 hour and 30 minutes, stirring a few times during. This length of time is important as it tenderises the beef and marries the flavours together.
Remove the lid and simmer for a further 10-15 minutes, or until the sauce thickens. Timings will vary depending on how much it reduced during simmering. It should still be nice and saucy, but not watery. Stir in the parmesan until it melts, then check for seasoning and adjust if needed.
Add the spaghetti to salted boiling water and cook until al dente. Drain and serve the bolognese poured over the spaghetti with extra parmesan.
Optional: To mix the bolognese and spaghetti together, make sure you undercook the pasta by a minute and reserve 1-2 cups of the pasta water. Add half the bolognese to a large pan over medium heat and add half the spaghetti with a good splash of pasta water. Toss until the spaghetti turns red and the sauce thickens, clings to the pasta and is no longer watery. Serve then repeat with the second batch. If you have a very large pan you can try one batch, I just find it easier tossing in smaller batches.