In heavy-bottomed sauce
pot, over low heat, add the vinegar and reduce it by half, stirring constantly. Add the sugar, coffee
and further reduce by 1/3 volume, continue to stir throughout this step. Remove from the heat when you have 3/4 cup liquid remaining. Pour the glaze through a strainer
into a small bowl, discarding the solids.
Preheat the grill to 300 degrees F.
Season the beef tenderloin with salt and pepper, to taste, and put on the preheated grill
. Cook on each side until desired temperature is reached, about 7 to 8 minutes for medium-rare. Remove from the grill and evenly brush the tenderloin with the balsamic glaze
. Return the beef to the grill for 5 minutes, allowing the glaze to coat the meat. Remove the tenderloin from the grill to a cutting board and let rest for 5 minutes. Slice, arrange on a serving platter and serve.