Preparation

Preheat the grill to a medium-high heat. Slice the ends off the grapefruit.
Cut 3/4 inch thick rounds, yielding about 3 or 4 slices. Combine the sugar
and cinnamon. Sprinkle the sugar mixture on both sides of each slice.
Grill the grapefruit for 5 minutes or until the slices are hot and the sugar begins
to caramelize. Make sure to turn the slices halfway through cooking.