Ditchi
Cut the ciabatta bread in half.
Slice the onion, tomato, and lettuce into appropriate sizes.
Thinly slice chicken breast or smoked duck.
Spread whole grain mustard sauce on the inside of the ciabatta bread.
Layer lettuce, tomato, onion, and sliced chicken or duck on the bread in order.
Add a slice of cheese if desired.
Cover with the top half of the bread and press gently to make it easy to eat.