Parmesan, Gouda or Italian-style cheese, sliced
Cut the bread into 12 thick slices (3 slices per sandwich) and toast them.
Fry the prosciutto until crispy in some olive oil and allow to drain on paper towels.
Mix the yogurt with the raspberry jam and lemon juice, to your taste.
Spread butter on one side of each of the slices of bread. Cover with lettuce, chicken, slices of tomato and cucumber and sprinkle with the yogurt mixture. Place another slice of bread on top and cover with lettuce, cheese, prosciutto and onions. Then place the last piece of bread on top securing it with toothpicks. Continue to do the same with the other three sandwiches.