step 1
Preheat oven to 180 (160 fan). Place trout fillets in a single layer in a buttered roasting tin, and sprinkle with black pepper.
step 2
Cover tightly with foil and bake for 15 mins or until fish is opaque and flaky.
step 3
Watercress sauce: place creme liquide, watercress, butter, flour, lemon juice and egg yolk in food processor, season with salt and pepper. Puree until smooth.
step 4
Transfer mixture to saucepan and cook gently, stirring constantly, until sauce thickens.
step 5
Serve the trout hot accompanied by watercress and lemon sauce with frsh sprigs of watercress.