1) Soak two 12- x 7-inch (30 x 18 cm) untreated cedar planks in water for at least 30 minutes or for up to 24 hours.

2) Place salmon fillets on top of each plank.

3) In small bowl, whisk together oil, lemon rind and juice, chives, mustard, salt and pepper; brush some over salmon.

4) Place planks on grill over medium-high heat; close lid and cook, brushing with remaining lemon mixture for about 20 minutes or until fish flakes easily when tested with fork.

5) Dill Sauce:Meanwhile, in small bowl, combine sour cream, cucumber, dill, chives, salt and pepper.

6) Serve planks on platter with dill sauce.