Wash the trout (if excluded) under running water and dab with kitchen paper. Now lightly sour with lemon juice. Season with salt and pepper inside and out. Now lightly flour in flour and fry in a pan until golden. Arrange on a plate or platter and pour the butter from the pan over it (but should only be made if the butter is not too dark).
Now cut off a lemon wedge and remove the peel. Arrange on the plate / plate together with the tomato slices (either on or next to the fish). As a side dish, give fried potatoes or French fries extra, but e.g., Boiled potatoes can be competed and placed next to the fish.