Onions peel, halve and cut slices. Wash the chillies, dab dry and halve lengthwise, then cut into very thin strips. Wash and clean the cucumber and slice lengthwise in thin slices. Put cucumber slices, chilli, vinegar, oil and onions in a bowl and season with salt, pepper and sugar. Cut bread into cubes and distribute on 4 skewers. Grill meat and skewers on the grill on both sides for 3-4 minutes, then season with salt and pepper if necessary. Arrange meat, steak sauce and cucumber salad and garnish with marjoram