Put the frisée in a large salad or mixing bowl. Finely grate the 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 the oil, and season to taste with salt and pepper. Add just enough of the dressing to the frisée to coat it lightly. Mound the frisée on four salad plates, scraping any red onion remaining in the bowl over the frisée. Arrange the orange slices on top, scatter with the pistachios, and serve immediately.
nutrition information (per serving):
Photo: Scott Phillips