In a large pot or Dutch oven, heat coconut oil over medium heat. Add diced onion and cook until softened, about 5 minutes.

Add garlic, ginger, red curry paste, cumin, and coriander to the pot. Cook for 1 minute more, stirring constantly.

Add butternut squash and broth to the pot. Bring to a boil, then reduce heat and simmer for 20-25 minutes, or until squash is tender.

Carefully transfer the soup to a blender (or use an immersion blender) and blend until smooth.

Return the soup to the pot and stir in coconut milk. Heat through.

Serve hot, garnished with cilantro, chopped peanuts, and a drizzle of sriracha (optional).