1. Chop finely one of the cauliflower; sweat in a little olive oil and salt, then add the milk and cream and cook quickly until just tender.
2. Strain, keeping the liquid.
3. Blitz in a food processor with some of the liquid until you obtain and smooth puree, adding a little lemon juice as desired. Keep whatever liquid is left over.
4. Slice thin cross sections of the other cauliflower and colour very quickly in a hot pan, so they still retain some bite.
5. Pulse some raw florets in a food processor until it resembles couscous, then mix with the herbs, nuts, some salt, lemon juice and olive oil.
6. Sear the scallops in a hot pan. Serve with the cauliflower couscous, puree, roast slices, and sorrel leaves. Finish the plate by frothing the hot cauliflower milk with a hand blender and spoon over the dish.