Cut the cauliflower and broccoli florets into strips.
Divide the Romanesco broccoli into very small tufts.
Bring a saucepan of water to the boil with a pinch of salt, one of sugar and 40 g of white wine vinegar.
Dip the cauliflower florets in the water and boil them for 3-5 ’; drain them, then boil the broccoletti for 2-4'e for last the tufts of Roman broccoli for 2-3 '. Briefly dip all the vegetables in water and ice to stop the cooking and keep the colors bright.
Drain them and dry them gently with kitchen paper.
Blend the milk with the immersion blender, adding 120 g of oil, a little lemon juice and a pinch of salt.
and a teaspoon of sesame seeds. At the end add a dozen chopped chervil leaves.
Spread the boiled vegetables on the plates and complete them with a generous spoonful of mayonnaise. Serve the rest of the mayonnaise in small bowls.