Split a grapefruit in half and place it on a baking tray or in an oven-proof pan. Sprinkle the pink halves evenly with sugar and top with just a tiny bit of salt to bring out the flavor.
Place the grapefruit halves under the broiler until they turn bubbly and a little brown (or even black) around the edges. This usually takes about 3 minutes, but monitor it because every broiler is different. Don’t get distracted! Overbroiling ruins a good meal fast.
If you have maple syrup on hand, use it instead of sugar for even more flavor.
