Melt butter in skillet over medium flame; when very hot but not smoking, brown steaks quickly, 2 minutes on each side; add lemon juice and sherry; season with pepper to taste; heat 1 minute only; remove from heat. Place halibut in shallow glass dish; pour pan juices over; garnish with nuts and smoked salmon. Bake at 180ºC or 10 minutes or until fish flakes with a fork.