Wash the trout and pat dry. Season with pepper and salt inside and out. Rinse off the rosemary, pat dry and place a sprig in each trout. Rinse the parsley, pat dry, pluck the leaves and add them to the trout with the rosemary. Now roll the fish in flour.
Heat the olive oil and butter in a pan. Fry the trout in the hot fat on each side for about 5 - 10 minutes (depending on the size of the fish) until brown. Arrange on plates with a lemon wedge each.
If you want, you can pour some fat from the pan over the trout. This goes well with salad and puree or boiled potatoes.