Ruby Red Grapefruit Panna Cotta

1. Arrange six 6-ounce serving dishes on a baking sheet. Cut five of the grapefruits in half and juice them over a small saucepan. Sprinkle the gelatin evenly over the grapefruit juice and let it bloom until the gelatin softens, 5 to 10 minutes.

2. Heat the grapefruit juice mixture over medium-low heat and stir until the gelatin dissolves, about 3 minutes. Remove from heat and set aside.

3. In a small saucepan, bring the heavy cream, salt, ⅓ cup of the sugar and one half of the vanilla bean half to a simmer over medium heat. Stir occasionally until the sugar is dissolved, about 5 minutes.

4. Remove the pot from the heat and discard the vanilla bean pod. Gradually whisk the grapefruit-gelatin mixture into the cream. Transfer the mixture to a container with a spout, such as a large liquid measuring cup.

5. Gently pour the mixture into the serving dishes. Transfer the baking sheet to the refrigerator and chill until set, at least 2 hours and up to overnight.

6. Before serving, cut the remaining grapefruit into segments; reserve the juices.

7. In a medium saucepan, combine the grapefruit segments, the reserved juices, the remaining 2 tablespoons sugar and the remaining vanilla bean half. Bring to a simmer over medium heat and stir until the sugar has dissolved and the mixture thickens slightly, about 2 minutes. Remove the pot from the heat and discard the vanilla bean pod.

8. To serve, top each panna cotta with grapefruit segments and 1 to 2 teaspoons of syrup.