Heat the oven to 220C/200C fan/gas 7. Put 1 tbsp of the rapeseed oil in a small frying pan and tip in the onion, cumin and garlic, then fry over a medium heat for 8 mins until softened and golden. Tip into a bowl. Add the cooked quinoa, beetroot, flour, flaxseed and coriander, and mix until combined. Season lightly. Leave to sit for 5 mins to bind.

Divide the mixture into four – it will be quite loose – then, using wet hands, shape them into patties. Put the burgers on a lined baking tray and put in the oven for 15 mins. Turn them over and cook for another 10 mins.

Meanwhile, make the salad dressing. Whisk together the beetroot liquid, lemon juice, yogurt and oil, and season.

To serve, pile the rocket onto plates and place a burger on top. Drizzle over the dressing and scatter over the extra coriander.