Place a large lidded frying pan over a medium high heat. The pan should be wide enough to fit your spaghetti, without breaking it.
Add the oil to the pan and fry the mushrooms until lightly golden. This should take 5-6 minutes. You might need to do this in two batches depending on the size of your pan. Once the mushrooms are cooked - add the shallots, garlic and herbs. Cook until the shallots are translucent and the garlic is fragrant, 1-2 minutes, taking care to stir the pan so that the garlic doesn't burn.
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.
I like to use a mix of button mushrooms and baby portabella mushrooms. You can use any variety you prefer!
Whole milk can be used if you are not looking to make a dairy-free recipe.
If using water rather than broth, you may wish to add a bit of additional salt and pepper.