For the rainbow trout with olives and potato slices, first peel the potatoes and cut them into thin slices. Fry them sharply on both sides in a little rapeseed oil.
Core the bell bell pepper and cut into small cubes. Cut the olives into coarse pieces.
Lay 4 sheets of baking paper (20 x 30 cm) flat. Brush the two short edges with egg white and fold inward about 2 cm. Place trout in the center of the sheets and arrange potatoes, peppers and olives on top. Pour wine over them, place a tablespoon of butter on each and season with dill, salt and pepper.
Brush the still open side of the baking paper sheets with egg white and fold over the fish. Press down lightly and steam the packets on the grill over indirect heat for about 15 minutes.
Open the packets and serve the rainbow trout with olives and slices of potatoes.