Wash the marjoram, shake dry and remove the leaves from the stalks, except for something to garnish. Drain capers and chop.
Mix vinegar, mustard and sugar. Fold in 4 tablespoons of oil in a thin stream. Stir in capers and chopped herbs. Season to taste with salt and pepper. Set aside.
Cut bread into cubes. Heat 3 tablespoons of oil in a frying pan. Fry the bread cubes for about 2 minutes while turning them until crispy. Drain on kitchen paper. Peel onion and cut into fine rings.
Cut the cheese into slices.
Place the cheese in a fan shape on a plate. Spread the dressing, onion rings and bread cubes on top. Garnish with remaining marjoram.