These are made with one vegetable, such as the carrots here, or with several. Leeks or onions are usually added for flavour. The technique is to cook the vegetables until very soft for easy puréeing. For enriching after puréeing.
Swear diced vegetables in butter over a moderate heat, stirring frequently, for 3-4 minutes until they soften.
Add stock or water to cover, and seasoning to taste. Simmer until very soft, about 20 minutes.
Pureé in a blender, then reheat in a clean pan. Check both the seasonings and the consistency.