Blitz walnuts and mushrooms together and mix with oil and salt
Bake at 200C/400F for 30 minutes, stirring after 15 minutes
Finely chop onion and celery, then sauté in oil
Add tomato paste and miso (optional) and roast briefly
Deglaze the pan with balsamic vinegar
Add the roasted walnut and mushroom mixture to the pan
Add water, salt, pepper, paprika, dried herbs, and bay leaves
Stir and simmer for at least 20 minutes
Cook pasta al dente separately
Finish cooking pasta in the sauce with some pasta water
