Soak your dried mushrooms in 100ml boiling water for 30 mins until soft. Remove from the liquid (but reserve it till later!) and chop to a fine dice. Set aside.
Bring 1 tbsp oil to a high heat in your large frying pan. Add your fresh mushrooms in batches and fry until the liquid absorbs off and they start to caramelise (as you would with meat!). Repeat with your remaining mushrooms, then set aside.
In a large cast iron pan, add 3 tbsp olive oil over a low-medium heat. Add your onion, celery, carrots and peppers. Cook them for about 20 mins until they are starting to soften. Add your garlic and cook out for 2 mins before adding your tomato puree and cooking out for 5 mins.
Add your wine and reduce down totally, before adding your vegetable stock and tinned tomatoes. Pop your mushrooms (fresh and dried) back into the pan along with the dried mushroom liquid and your parmesan rind, bay leaf and oregano. Bring to a boil, then simmer on a low heat for an hour or so.
Add your miso paste, stir to combine and season to taste.
Add your spaghetti and stir through with a cup full of pasta water until you have a smooth sauce coating each length of pasta.