At least 1 hour before grilling, soak plank in enough water to cover. Weight down plank to keep it submerged during soaking. Drain plank.

Thaw salmon, if frozen. Rinse salmon; pat dry with paper towels.

In a small bowl, combine lime peel, lime juice, salt, and pepper. Brush lime mixture over both sides of salmon.

For a charcoal grill, place plank on the grill rack directly over medium coals; heat about 5 minutes or until plank begins to crackle and smoke. Place salmon on plank. Cover; grill salmon for 15 to 20 minutes or until fish flakes easily when tested with a fork. (For a gas grill, preheat grill. Reduce heat to medium. Grill salmon as above.)

Serve salmon on sourdough rolls topped with Apple Slaw. Makes 4 sandwiches.

Apple Slaw: n a medium bowl, stir together 1/2 teaspoon finely shredded lime peel, 2 tablespoons lime juice, 1 tablespoon olive oil or salad oil, and 1/8 teaspoon salt. Add 1 cup slivered tart red apple; 1 cup shredded green cabbage; 4 very thin onion slices, halved and separated into rings; and 1 tablespoon snipped fresh cilantro. Toss mixture to combine. Cover and chill for up to 1 hour, stirring once. Makes about 2 cups.