In a saucepan, heat the oil over medium heat. Add the onion and garlic. Cook, stirring, for 6-7 minutes until soft.
Add coriander, cumin (in my seeds, but ground is better) and chili pepper. Increase the heat and cook, stirring, for 2 minutes.
Then add the cauliflower, broth and water. Cover with a lid and bring to a boil. Reduce the heat and simmer for 30 minutes until the cabbage is soft. Remove from the heat and leave under the lid for another 20 minutes.
Then whisk in a puree in a blender or food processor.
Return to the stove. On low heat, add cream or sour cream and heat the soup well. Season with salt and pepper. When you add pepper, do not forget that there is already a little chili pepper in the soup.