Frisee Salad with Oranges and Pistacios

1 large or 2 small heads frisee, rinsed, diced, and torn into bit-size pieces
2 blood or navel oranges
2 tablespoons sherry vinegar
1 teaspoon honey
3 tablespoons finely diced red onion
1/3 cup olive oil
salt and pepper
? cup toasted pistachios

Put frisee in large bowl.
Finely grate zest of one of the oranges into a small bowl. Slice the skin from both oranges and cut the orange sections away from the dividing membranes. Put the sections in another bowl.
Add the vinegar, honey, and onion to the zest. Whisk in oil and season to taste with salt and pepper.
Add just enough of the dressing to the frisee to coat it lightly.
Mound the friseee on salad plates, scraping any red onion remaining in the bowl over the frisee. Arrange oranges slices on top, scatter with pistachios, and serve immediately.