Remove the skin and seeds from the pumpkin, and cut it into bite-sized pieces.
Chop the onion and carrot into appropriate sizes.
Add butter to a pot and sauté the onions and carrots.
Add the pumpkin and stir-fry together.
When the vegetables are soft, pour in water or vegetable broth.
Once all ingredients are cooked, blend them smoothly using a blender.
Transfer back to the pot, add milk and salt, and bring to a boil.
Season with pepper, serve in a bowl, and finish.