Asian Lime Vinaigrette:
1 small fresh serrano chili
1 large garlic clove, minced
1 tablespoon packed dark brown sugar
3 tablespoons fresh lime juice (about two medium limes)
1 1/2 tablespoons Asian fish sauce
3 large grapefruits, peeled and segmented, see cook's notes
3/4 pound jicama, peeled and coarsely shredded (about 3 cups), see cook's notes
1 medium carrot, peeled, grated or finely shredded (about 1/2 cup)
1/3 cup plus 2 tablespoons packed fresh cilantroleaves
2 tablespoons pistachios, toasted, crushed
Prepare vinaigrette: Cut chili in half lengthwise.
Scrape out seeds and mince, being careful to wash your fingers and knife when you're done.
You should have about 11/2 teaspoons.
In a small bowl, whisk the chili, garlic, brown sugar, lime juice and fish sauce until the sugar dissolves.
Prepare salad: In a large serving bowl, toss together the grapefruit segments, jicama, carrot and 1/3 cup cilantro leaves.
Add just enough of the vinaigrette to lightly coat the grapefruit and vegetables.
Scatter the pistachios over the salad and garnish with the remaining 2 tablespoons of cilantro leaves.
Cook's notes: To segment grapefruit, cut top and bottom off citrus, making those two cuts parallel to each other and cutting below white pith.
Place cut side down on work surface.
Cut off peel and pith in strips about 1 inch wide, starting at the top of the fruit and cutting down, following contour of shape.
Working over bowl to collect juice, use a small sharp knife to cut parallel to one section's membrane, cut to center; turn knife and cut along the membrane on the other side of that section to remove it.
Repeat until all sections are removed and cut from their membranes.
A food processor shreds the jicama and carrot fastest, but you can use a box grater if you prefer.
Feel free to make this a few hours in advance but don't add the vinaigrette to the salad until you are ready to serve.