- Wipe the steelhead trout fillet dry with paper towels. Combine remaining ingredients in a bowl and mix well. Pour mixture over the trout fillet, making sure it is coated on both sides. Marinate for at least one hour before cooking.
- Preheat broiler or grill. Cook the steelhead trout, turning once — five to six minutes each side for medium rare.
- Place the steelhead trout on a serving platter and garnish with lemon wedges and sprigs of thyme.