Prepare the pumpkin by peeling, seeding, and chopping it into cubes.
Heat olive oil in a large pot over medium heat. Add the chopped onion, and sauté until translucent, about 5 minutes.
Add the minced garlic and grated ginger. Sauté for an additional minute or until fragrant.
Stir in the red curry paste, coating the onions, garlic, and ginger well.
Add the pumpkin cubes and broth, bringing the mixture to a simmer.
Continue to simmer until the pumpkin is fork-tender, about 15-20 minutes.
Remove the pot from heat and carefully blend the soup using an immersion blender or in batches with a regular blender.
Stir in the coconut milk and lime juice, then return to low heat to warm through.
Taste and adjust seasoning with salt and pepper as necessary.
Serve hot, garnished with chopped cilantro.