Heat the olive oil in a large frying pan. Fry the bacon over a high heat for a couple of minutes until it is browned and crisp.
Reduce the heat to medium. Add the onion, carrot, celery and garlic and fry for around 8-10 minutes until soft.
Add the mince and fry until browned. Add the tomatoes and oregano, along with the stock and coffee. Cover and simmer on a very low heat for around 45 minutes until the sauce is thick and nicely reduced. Season with freshly ground black pepper.
Meanwhile, cook the spaghetti to the packet instructions. Divide the spaghetti between four plates and spoon over the bolognese. Grate over some parmesan and serve immediately.