Preheat oven to 400 F.
Toss sweet potato, carrots, garlic, and olive oil together in a bowl and then place them on a baking sheet and roast for 25 minutes or until tender.
Combine sweet potato, carrots, garlic, nutritional yeast, salt, coconut milk in a blender or food processor and puree into a sauce.
Cook pasta as directed on the package.
Sauté broccoli or cauliflower if desired.
Combine sauce with the pasta over medium heat. Thin out the sauce with ~¼ cup pasta cooking water as needed.
Stir in broccoli or cauliflower.