Preheat the oven to 200°c and line a baking tray with baking paper. Add the pumpkin, carrot, garlic and onion on the tray, add a light drizzle of olive oil and a pinch of salt. Toss to combine. Place in the oven to cook for 30-40 mins until golden/tender.
When the vegetables are nearly ready, cook the pasta according to package instructions. Once vegetables are ready, allow to cool for 5 minutes.
Add the walnut topping ingredients to a small blender jug and pulse until fine.
Add the vegetables, soy milk, nutritional yeast, lemon, salt, pepper and seasonings to a high speed blender, blend on high until creamy (Note – You can start with half the soy milk and add the remaining as you go. It’s forgiving this way especially if you’re using more or less pumpkin/carrot).
Pour the sauce into a pan over medium heat, add the pasta and combine. Serve with the walnut topping and sage leaves.