Preparation
Place the salmon and milk in a large saucepan, season with salt and pepper, bring to simmering point and poach gently for about 15 minutes.
Meanwhile, place the onion, parsley, olive oil and lemon juice in a shallow dish and mix well.
Drain the fish and place in the onion mixture.
Turn to coat then cover and leave to marinate for 1 hour, turning from time to time.
Preheat the grill to very hot and line the grill pan with aluminium foil.
Transfer the fish to the grill pan and cook for 5 minutes on each side or until lightly browned and heated through.
Serve immediately.