1 large salmon fillet (skin on)
1/2 cup butter
Salt and Pepper to taste
1 cup brown sugar
Dijon or other spicy mustard
1/2 cup dark rum
Line the top of a grill with greased foil before you being. Salt and pepper the salon fillet to taste, then spread on a thin layer of the mustard. When grill is hot, place salmon fillet, skin-side-up, on the greased foil, and cook for about 5 minutes. While the salmon is cooking, melt the butter in a saucepan and mix in brown sugar and rum.
The sauce should be of a thick paste consistency. (Add a little more brown sugar, if necessary.)
Turn fillet over, spread with a little more mustard, and baste with the butter mixture. Cook and baste for about 5 minutes more or until salmon is flaky, but not dry. Be sure not to overcook.