Place a large lidded frying pan over a medium high heat. Add the oil to the pan and fry the mushrooms until lightly golden. This should take 5-6 minutes. Once the mushrooms are cooked, add the shallots, garlic and dried herbs. Cook for another 1-2 minutes.
Add the vegetable broth (or water). Add the spaghetti, 2 cups of the dairy-free milk (reserving half a cup), salt, nutritional yeast and miso. Cover the pan and bring it to a boil.
Remove the lid, reduce to a simmer and cook for 8 to 10 minutes or until the pasta is cooked, stirring every minute or so to make sure the pasta doesn't clump together.
When the pasta is cooked, remove the pan from the heat, and add the reserved half cup of milk and stir it through. Serve immediately.