Cut: Trim a bit of the peel off the bottom of each grapefruit half so that it sits upright. With a paring knife, gently loosen the segments of grapefruit and remove seeds,
Dry: Place cut side down on a few layer of paper towels for 5 to 10 minutes to remove excess moisture.
Torch: Sprinkle 1 tablespoon of sugar on each half. Use a kitchen torch to melt and lightly brown the sugar. While sugar is still hot, sprinkle with a pinch of coarse sea salt.
Serve: Let cool then and serve with a dollop of mascarpone and roughly chopped pistachios.
Video
Notes
Broiler Method: No kitchen torch? You can broil in the oven, watching carefully, for 5 minutes, or until sugar is melted and lightly browned.