Quinoa sushi with pickled ginger

Quinoa is an ancient variety of grain from South America that has become fashionable for its high protein content and gluten-free properties. It is available from health shops at a fairly hefty price. You can, if you want, use sushi rice instead.Ingredients60g fresh root ginger, peeled and very finely slicedSalt1 small piece raw beetroot (it gives the ginger a lovely pink hue)Tezu (vinegar pickling liquid)60ml (4 tbsp) brown rice vinegar30ml (2 tbsp) water10ml (2 tsp) runny honey or light agave...