Heat butter and olive oil in a large pan over medium to high heat.
Add the chorizo and fry it off for 3-4 minutes, or until it's starting to brown.
Remove chorizo and place on a plate lined with paper towel.
Add onion and carrot and fry for 2-3 minutes in the chorizo oil.
Add garlic and stir on low for 3-5 minutes, until onion is opaque.
Add the tomato paste and tomatoes and stir.
Add red wine and beef stock, gently scraping the bottom of the pan with a wooden spoon to release the flavours.
Cover and simmer on low heat for 25 minutes. If it starting to get too dry, add an extra ½ cup of beef stock.
Add chorizo, and simmer 15-25 minutes uncovered until the sauce thickens.
Meanwhile, cook pasta according to packet direction.
In the last 5 minutes of cooking, add the mushrooms to the pasta sauce.
Strain and serve the pasta and sauce with freshly grated parmesan cheese.