Thinly julienne the onion and fry in a pan with a dash of oil until colored and juicy.
Once all the water has evaporated, add 1 tablespoon of sugar and cook until completely dissolved. Set aside.
Put 3 sliced of buttery cheese, 1 tablespoon of shredded blue cheese, and half the caramelized onion on a tortilla. Cover with another tortilla and do the same with the others.
Put the tortillas on a grill or in a preheated oven for ten minutes.
Then assemble on a platter and arrange the serrano ham slices, arugula and strawberries on top. Serve immediately.
