method
1. Combine the melted butter with the mustard, lemon juice and seasoning to taste.
2. Brush half this mixture over the steaks, on both sides, then grill the fish over medium coals for 10 minutes.
3. Turn, brush with the remaining mixture and grill for a further 10 minutes.
4. Serve hot, with any of the remaining mustard mixture and lemon slices to garnish.
