You could switch out the mustard for another "sticky" substance and add herbs and spices to the sugar for different flavors.
1 salmon filet
Preheat your grill to high.
Spread just enough mustard on the salmon to cover with a thin coat. Next put enough brown sugar to cover the filet on a plate. Mix the cayenne pepper with the figure. Put the salmon, mustard side down into the sugar. Make sure the sugar evenly coats the whole filet. Put the filet on the grill and cook until it reaches the desired doneness. Serve immediately. In the picture I served over sautéed spinach with mushrooms and bacon crumbled over it.