To prepare the pearl barley, place all the ingredients in a pan and bring to a boil. Reduce the flame and simmer for 20-30 minutes until soft and tender. Drain and chill.
To make the quinoa, place all the ingredients in a pan and bring to a boil. Reduce the heat and simmer for 10 minutes. Take off the hob and cover until all the liquid has been soaked by the quinoa. Chill until required.
For the cauliflower milk and purée, skim the top layer of small florets off each cauliflower; you should end up with 600 g in all. Sweat the cauliflower shavings in the olive oil with some of the salt until they start to soften.
Add the milk/soya milk and water and bring to a simmer. Cook for 5-10 minutes or until cooked. Pass through a strainer, retaining the liquid.
Blitz the cauliflower with enough of the milk to form a purée. Strain through a sieve and season with salt and some lemon juice. Use a tad of the purée to flavour the milk and season with salt and lemon juice.
To prepare the cauliflower and Romanesco slices, cut the florets into slices by cutting them in half lengthways and then using a mandolin to slice 1-2 mm thick slithers of the cut faces. Place on a tray and cover with a damp cloth.
For the cauliflower and Romanesco pickles, place all the ingredients excluding the florets in a pan and bring to a boil. Remove from the heat and leave to permeate for 30 minutes. Pass through a sieve when ready.
Split the liquid between two small pans and bring to a boil. Place the cauliflower in one and the Romanesco in the other and bring both back to the boil. Remove from the heat and chilll in the liquor.
To prepare the cauliflower couscous, shave the top layer of small florets off the cauliflower; you require 160 g in total.
Put the cauliflower florets on a chopping board and cross chop it with a knife until it resembles the texture of couscous. Combine with and equivalent amount of pearl barley and quinoa.
Distribute each element of the dish across the serving dish, ensuring there is a good balance of texture and colour. Serve immediately.