Preheat oven to 375. Line a roasting pan with parchment paper.
Peel, remove seeds and cube butternut squash, cut the onion in 4 and mash garlic cloves. Add everything to the roasting pan. Drizzle with avocado oil, salt, pepper and sage and mix well. Add the rosemary sprigs.
Roast for 45 minutes, mixing halfway through.
Add the cooked vegetables to a pot. Heat over med-low and add the can of coconut oil and the nutritional yeast. Mix everything together with a wooden spoon.
Using an immersion blender, blend until smooth. Alternatively, add contents to a countertop blender. If the mixture is too thick, add some water to thin it and blend again until desired consistency is reached.
Add sauce to your favourite cooked pasta and enjoy!
