Preheat oven to 400 degrees F. Coat a large roasting pan with cooking spray.
Season salmon with salt and black pepper and place in roasting pan. In a small bowl, whisk together lemon juice, rice wine and miso paste. Brush mixture all over salmon in pan.
In a large bowl, combine potatoes, oil, garlic, rosemary, and salt and black pepper to taste. Toss to coat potatoes. Arrange potatoes alongside salmon (or on a separate baking sheet if there's not enough room).
Roast salmon and potatoes 20 to 25 minutes, until fish and potatoes are fork-tender.
Serve 4 of the salmon fillets with the cilantro sprinkled over top and all of the potatoes on the side. Reserve remaining salmon for salad.