Instructions

1. Begin by peeling the grapefruits, removing as much of the bitter white pith as possible. Segment the grapefruits by carefully cutting between the membranes to release the juicy segments. Set these aside in a bowl.
2. In a small saucepan, combine the granulated sugar and water. Heat over medium heat, stirring occasionally, until the sugar is completely dissolved and the mixture is clear.
3. In a separate bowl, whisk together the cornstarch, lemon juice, and vanilla extract to create a smooth slurry.
4. Gradually pour the cornstarch slurry into the saucepan with the sugar mixture, whisking constantly to prevent lumps from forming.
5. Bring the mixture to a gentle boil, then reduce the heat and let it simmer for about 2-3 minutes, or until the sauce has thickened to your desired consistency.
6. Remove the saucepan from the heat and allow the sauce to cool for a few minutes. This will help it thicken even further.
7. Gently fold in the grapefruit segments, ensuring they are well-coated with the sauce.
8. Serve the grapefruit sauce warm or chilled, drizzling it over your favorite desserts or as a vibrant topping for savory dishes.