Place coriander in a pie plate. Season the hamachi with salt and pepper and press both sides of hamachi into coriander. Coat a sauté pan over high heat lightly with oil and sear the hamachi on both sides, about 30 seconds a side. To make salad, in a large bowl, combine fennel, lime juice, grapeseed oil and chives. Check for flavor and season; let macerate for 5 minutes. To serve, place a small mound of fennel salad in center of plate and top with thinly sliced hamachi.