Poach trout fillets in a court-bouillon made of equal parts dry white wine and water, and seasoned to taste with salt and freshly ground black pepper.
Transfer fillets to a well-buttered ovenproof dish and keep warm. Add
Combine double cream and egg yolks in a small bowl; stir in
Pour sauce over trout fillets; sprinkle with freshly grated Gruyère and glaze under preheated grill until sauce is bubbly and golden.