Put a large saucepan on a medium heat and add 1 tbsp olive oil.
Add 4 finely chopped bacon rashers and fry for 10 mins until golden and crisp.
Reduce the heat and add the 2 onions, 2 carrots, 2 celery sticks, 2 garlic cloves and the leaves from 2-3 sprigs rosemary, all finely chopped, then fry for 10 mins. Stir the veg often until it softens.
Increase the heat to medium-high, add 500g beef mince and cook stirring for 3-4 mins until the meat is browned all over.
Add 2 tins plum tomatoes, the finely chopped leaves from ¾ small pack basil, 1 tsp dried oregano, 2 bay leaves, 2 tbsp tomato purée, 1 beef stock cube, 1 deseeded and finely chopped red chilli (if using), 125ml red wine and 6 halved cherry tomatoes. Stir with a wooden spoon, breaking up the plum tomatoes.
Bring to the boil, reduce to a gentle simmer and cover with a lid. Cook for 1 hr 15 mins stirring occasionally, until you have a rich, thick sauce.
Add the 75g grated parmesan, check the seasoning and stir.
When the bolognese is nearly finished, cook 400g spaghetti following the pack instructions.