In a rectangular dish, mix miso, honey, rice wine vinegar, sesame oil, garlic, and juice of a small lime.
Place salmon (skin side up) in marinade. Cover and let sit in fridge for 1-2 hours.
Remove salmon from marinade. Brush off any excess marinade on the salmon flesh (the miso can burn quickly when cooked) and pat off any liquid that may have gotten on the skin (dry skin=crispy skin).
Heat grill to medium. Using canola oil grease the grates of the grill. The remaining oil should be brushed on the skin of the salmon. Sprinkle skin on salt.
Place salmon skin side down on the grill and cover. Let the salmon cook a majority of the time skin side down. Cook for approximately 5 minutes for a 1 inch thick file. Cook longer for a thicker piece of salmon. The fish will begin to get opaque as is cooks so you can gauge the 'doneness" of the filet.
Flip the salmon and cook for 1-2 more minutes on the other side. (I like my salmon cooked medium. Fell free to cook longer if you prefer a more well done fish.)
Plate and garnish with sesame seeds and green onions, if desired. Serve warm.