Soak the cashews in water (make sure they are fully submerged in water) for a minimum of one hour, but overnight is best. The longer you soak them, the creamier the sauce will be.
ROAST VEGGIES:
Move the oven rack to the middle position and preheat to 400°F.
Add the tomatoes, onion (cut in half, peeled, and placed flat side down), and garlic (with the peel on) to a baking sheet.
Drizzle olive oil, salt, and pepper all over the veggies and toss with your hands to ensure the olive oil and seasonings fully coat the veggies.
Roast the veggies for 30 minutes. Then, set the oven to a low broil and broil for 2 minutes, just long enough to blacken the skin on the outside.
MAKE PUMPKIN SAUCE:
Add the pumpkin puree, soaked cashews, roasted tomatoes, onion, garlic, non-dairy milk, oregano, salt, and pepper to the blender.
Blend on high for 1-2 minutes, or until the sauce is nice and creamy.
Once blended, taste to adjust the seasoning. Adding additional salt if needed.
SERVE:
Pour over a bed of hot pasta. Toss until fully coated, then sprinkle on fresh leaves of thyme (optional).
Notes
Is the pumpkin sauce too thick? Add additional milk of choice to help thin it out to the desired consistency. Are you looking for that traditional pumpkin/ fall taste? Add a pinch of pumpkin spice.