Put a large deep saucepan over medium heat and add olive oil. Add the onion, turmeric, ginger, garlic and chilli and cook for a few minutes.
Then add the sliced carrots, peppers and pumpkin. They should cook in the onion mixture for 10-12 minutes or until the vegetable slices are covered with the onion mixture and begin to caramelize and soften at the edges.
Next, add the vegetable broth and boiling water. The slices of vegetables should be completely submerged. Add more water if necessary.
Cook over medium / low heat for 30-40 minutes. When the vegetables are completely soft, whisk the soup with a blender to obtain a homogeneous mass.