In a large pot, heat olive oil and sauté onion until soft and translucent.
Add pumpkin puree, coconut milk, and red curry paste, and bring to boil.
Blend with immersion blender until smooth. Alternately, puree soup in blender in small batches, making sure to vent the blender. Return to pot and bring to simmer.
Serve hot, garnished with pepitas and chopped cilantro, if desired.