Start with the pickled red onion. Mix acetic vinegar, water and sugar, stirring until the sugar is dissolved. Finely slice the red onions and put in the fluid. Leave in the fridge for about an hour.
Make a coleslaw: mix mayonnaise with yoghurt, dijon mustard and tabasco sauce. Add the shredded cabbage, leeks, parsley and stir together.
Fry the quinoa burgers in plenty of oil in a frying pan until they have a nice colour. Serve with hamburger buns, pickled red onions, coleslaw and a sriracha mayonnaise.
