Heat the oil in a pan, sauté the garlic, add the quinoa and cook briefly. Pour in the bouillon, bring to the boil, cover and simmer over a low heat for approx. 15 mins. Allow to cool slightly. Mix the carrots, courgettes and salt, leave to absorb for approx. 30 mins. in a sieve, then press out all the liquid.
Mix the quinoa, vegetables, cheese, egg and flour, season. With wet hands, shape the mass into 4 small patties.
Heat the oil in a non-stick frying pan and fry the patties for approx. 5 mins. on each side.
Mix the mayonnaise with all the other ingredients up to and including the salt.
To assemble the burgers
Cut open the bread rolls, spread a little sauce over the bottom half of each roll. Cover with the spinach and red cabbage. Place the quinoa burger on top, spoon the remaining sauce over the top, cover with the top half of the bread roll, press down gently.