Cooking time: None

If you don’t have sherry vinegar, you can make the vinaigrette with 1 part grapefruit juice, 2 parts oil and a pinch of sugar.

1. Peel the grapefruit, removing the white pith; cut into supremes, i.e., sections without the membrane. Work over a bowl to collect the juice.
2. Peel and grate the carrots with a large grater.
3. Wash the cucumber well; dry it and slice on a mandolin into rounds or ribbons. Sprinkle lightly with salt.
4. Peel the onions and slice thinly, lengthwise.
5. In a bowl, whisk the oil and vinegar together to emulsify. Add the grapefruit juice. Allow 45 ml, squeezing one of the segments if necessary. Season with pepper.
6. Divide the vegetables among plates. Add the grapefruit supremes, drizzle with the vinaigrette and serve cold.