Make the marinade: mix the first 8 ingredients in a large bowl until the sugar is dissolved. Reserve ⅓ cup.
Place the steak into the bowl and swirl it around until fully covered. Cover with plastic wrap and refrigerate from 30 mins to overnight.
Preheat the grill, griddle or grill pan over high heat.
Grill the steak for 10-12 minutes on each side or until the internal temperature of the meat is 130 F on the thickest part.
Prepare the glaze: place the reserved marinade in a small saucepan and bring to a boil, reduce the heat and simmer until slightly thick. Remove from heat and stir in the butter.
Before slicing the meat, let it rest for about 10 mins. Brush with the glaze before serving and serve the glaze on the side.