Heat the olive oil in a large saucepan over medium heat.Saute onion about 5 minutes, stirring occasionally, but do not let it colour.
Add garlic, saute about 2 minutes. Be careful it does not burn.
Add the cauliflower, potato, vegetable stock and thyme leaves.Season with salt and freshly ground black pepper.
Bring the mixture a boil, then reduce the heat, and simmer 15 minutes, or until the vegetables are tender.Remove the saucepan from the heat and add the parsley leaves. See Note 3.
With a hand mixer, or in a blender, puree the mixture until smooth. See Note 4.Reheat in the saucepan, season to taste with salt and pepper. See Note 5.
Add a little finely zested lemon rind and some chopped parsley to the top of each of the bowls. See Note 6.
