Peel the pumpkin, onion, garlic and carrots, then cut all the vegetables into larger pieces.
Put baking paper on the baking pan and spread all the vegetables on it.
Add salt and oil to the vegetables and mix.
Bake for 35 minutes in a preheated oven at 200 °C (392° F).
When the vegetables are cooked, put them in a pot with 500 ml (2¼ cup) of water and one bouillon cube.
Mix everything together in a mixer or with a stick blender to get a creamy texture.
Then boil the soup and serve.