Pluck the romaine lettuce into individual leaves, wash and cut into small pieces. Clean, wash and cut the pepper into strips. Cut cucumber and tomato into slices. Stir yoghurt, milk and 1/4 teaspoon oregano until smooth, season with salt, pepper and lemon juice.
Wash the chicken filet and cut into strips. Mix with 1 teaspoon of oil and to taste with oregano, chili flakes, salt and pepper. Heat a pan and fry the meat until golden brown, turning it over.
Toast the toasties, cut them open, spread a thin layer of yoghurt-milk-mix. Cover lower halves with salad, meat and vegetables. Add 1 tablespoon of yoghurt mixture to each half. Place other toastie halves on top.
Garnish with parsley.