Finely slice the cabbage and place in a sieve. Boil the water, pour over the cabbage and drain. Combine the crema di balsamico and the lime juice in a bowl, season. Add the cabbage and mix together.
Cut the bagels in half and place on a baking tray lined with baking paper.
Bake for approx. 8 mins. in the centre of an oven preheated to 200°C.
Cut the avocado in half and remove the stone, slice the flesh.
Heat the oil in a non-stick frying pan. Fry the burgers for approx. 3 mins. on one side before turning them over. Put one slice of raclette cheese onto each burger, cover and cook for about another 3 mins.