Clean the pointed cabbage, cut into thin strips and wash. Drain well. Mix mayonnaise, yoghurt and lemon juice in a bowl and season with salt and pepper. Add cabbage and mix well.
Onions peel, halve and in fine strips cut. Place the jalapeño on kitchen paper and drain. Remove the rind from the cheese and cut into small pieces. Drain the tuna and pluck into large pieces.
Cut a pocket into each flatbread. Fill with tuna, coleslaw and the rest of the prepared ingredients.
Heat 1 tablespoon of oil in a second pan. Fry 1 sandwich in it on both sides for about 3 minutes, weighting it down with another pan or a heavy saucepan. Fry the rest of the sandwiches in 1 tbsp. of hot oil. Halve the sandwiches and arrange them.