Start by roasting the walnuts in a dry pan until hey get some color. While they are roasting, chop the onion, celery, carrot, chili and garlic. Fry the onion, celery and carrot in a saucepan in a little bit of cooking oil until they get a nice color. Then add the chili, garlic, thyme, bay leave and oregano. Let them fry for a few seconds then add the tomato purée. Let the purée get a nice color before you add the apple cider vinegar. Stir around in the bottom of the pot to bring forth the flavours.Then add the crushed tomatoes and let it simmer for about 20 minutes. Meanwhile you cook the pasta and fry the mushrooms.Season with salt and pepper. Serve with a hearty dose of parmesan or vegan cheese