Melt the butter in a frying pan over a medium heat, add the sugar and once the sugar has dissolved stir in the remaining marinade.
Keep stirring the bubbling marinade until it is a thick consistency.
Brush the warm marinade over the salmon fillets then grill the salmon for about 7 - 10 minutes, depending on how thick your fillets are. The salmon is cooked when the salmon is opaque and firm.
Halfway through cooking brush the salmon again and sprinkle the coriander over the salmon.
Any remaining glaze can be poured over the salmon when served.