Add the wine, 2 cups water, the vinegar, 1 teaspoon salt, and the peppercorns in a shallow pan. Bring to a boil over medium-high heat.
Reduce the flame to low and simmer for 5 minutes. Combine the chicken, cover, and poach until just opaque, 6–8 minutes, occasionally skimming off any foam on the surface.
Withdraw the chicken from the liquid and let cool for seven minutes, then cut into cubes.Meanwhile, in a dry frying pan, toast the pistachios over medium-low heat, stirring, till fragrant and starting to brown, approximately 6 minutes.
Pour onto a plate to cool.Cut the grapefruit segments in Half crosswise and put them in a bowl with the chicken and 1/2 of the pistachios.
Now you should add the mayonnaise, mustard, cilantro, lime juice, Half teaspoon salt, and ¼ to Half tsp pepper and blend well. Garnish the salad with the left pistachios and now serve.