Beef: Add a drizzle of olive oil to a large pot over medium high heat and add in beef. Fry and break up with your wooden spoon until it begins to brown. Season with a pinch of salt & pepper and continue frying until fully browned. Remove from pot and place in a side dish. Reduce heat to medium.
Chorizo: Add a drizzle more oil if needed, then add in chorizo, celery, carrot and onion. Fry until the chorizo begins to crisp and release oil with the carrot, onion celery just beginning to brown. Add in garlic and fry for 1-2mins longer.
Red Wine: Add in 2 tbsp tomato puree and fry off for a couple of minutes. Pour in red wine, deglaze the pan with your wooden spoon then leave to simmer and reduce for 5mins.
Cook: Add back in cooked beef, then pour in beef stock and tomato passata. Add sun dried tomatoes, bay leaves, rosemary and seasoning to taste. Give it all a good stir then pop on the lid and simmer for AT LEAST 1 hour 30mins. This is important to tenderize the beef and marry all the flavours together. Take off lid and stir once or twice during.
Pasta: Add spaghetti to heavily salted boiling water and cook until al dente. Reserve a mug of starchy pasta water before draining.
Reduce: Once you've simmered the beef with the lid on, take it off and allow it to reduce down for 10mins or so. I recommend adding a splash of starchy pasta water to help emulsify the fats in the sauce. You won't need much, no more than 1/4cup.
Serve: Serve bolognese over spaghetti and top with tiny basil leaves and parmesan. Enjoy!