Heat the butter or olive oil in a large pot over medium heat.
Add the chopped onion and cook until softened and translucent.
Add the minced garlic and cook for about 30 seconds.
Stir in the pumpkin puree.
Pour in the broth and stir until well combined.
Add the salt, black pepper, and nutmeg.
Bring the soup to a gentle simmer and cook for 15–20 minutes.
Blend the soup until smooth using an immersion blender or carefully blend in batches.
Reduce the heat and stir in the heavy cream.
Warm gently for a few minutes, taste, and adjust the seasoning.
Serve warm with your favorite toppings.