Trout En Croute
Rinse trout, pat dry, sprinkle inside and out with lemon juice and season with salt and pepper. Thaw puff pastry. Rinse parsley, shake dry and mince. Heat butter in a frying pan and add parsley, then add trout.
Preheat oven to 200°C (approximately 400°F).
Roll out pastry on a lightly floured surface. Add trout and roll up. Set aside a quarter of the dough for decoration. Combine egg yolk and milk and brush onto pastry. Decorate pastry, as desired, with remaining dough. Brush with remaining yolk. Grease the baking sheet with butter, place pastry onto sheet and bake for 30 minutes.
Line a plate with lettuce leaves. Remove trout from oven and place on lettuce.
Combine creme fraiche, mustard and horseradish. Serve trout with sauce.