Mix yoghurt with wasabi. Wash the lettuce leaf and dab dry. Wash, clean and slice the cucumber. Wash sprouts, drain well. Cut the buns in half horizontally once.
Wash the fish, dab dry and cut into pieces. Season with salt and pepper. Heat oil in a coated pan. Fry the fish for 2-3 minutes on each side. Drain on kitchen paper.
Cover the lower half of the roll with lettuce and cucumber. Add fish and yoghurt. Sprinkle sprouts on top, place lid on top and serve.