Begin by spiralising the squash into butternut spaghetti. You can opt to keep a little to the side to roast and serve alongside the final pasta dish if you wish.
Fry the onion in 1 tbsp olive oil and once sufficiently browned pop into the blender with the soaked cashews, garlic, salt, tamari, stock and blend until smooth in texture. You may need to stop the blender to scrape down the sides a couple of times to ensure the mixture is well combined. If the mixture seems a little too think add a splash more water or your favourite nut milk. Note, the sauce is supposed to be fairly thick and creamy.
Using the same pan you used for the onions, cook the butternut squash and the mushrooms until softened. Add the cashew sauce and spinach and bring to a gentle simmer.
While the dish is cooking through, pop a handful of extra cashews in the oven around 150 degrees to roast for 2-5 minute until crunchy and browned.
Once the sauce is sufficiently heated through and the spinach is nicely wilted, distribute between serving bowls.
Top and serve with the crunchy oven roasted cashews.
Side notes: For those who don't have access to a spiraliser, this recipe can be done using traditional gluten free pasta.