Separate the broccoli into florets. Carefully wash the leeks, then mince them. Peel the
potatoes and cut them into cubes. Peel and mince the onion.
Heat the olive oil in a large heavy pot. Add the onion and allow to sweat for 2 min.
Add all of the vegetables, stir while cooking for 2 min. Add 5 cups of water, the bay leaf, thyme and a bit of pepper.
Stirring, continue cooking for 15 min. Add the cumin (optional). Remove the thyme and bay leaf from the mixture and pour into the bowl of a mixer and blend at length. Return to large, heavy pot and slowly reheat. Pour into soup bowls.
Add the goat cheese and stir gently with a wooden spoon.