Warm Potato, Onion and Caper Salad

Warm Potato, Onion and Caper Salad
1 pound Idaho or Yukon Gold potatoes, scrubbed but not peeled
1 small red onion, sliced thin
1/3 cup chopped fresh Italian parsley
1/4-1/3 cup tiny capers, drained
1/3 cup extra-virgin olive oil
Salt (preferably sea salt)
Cracked or coarsely ground black pepper
Several teaspoons red-wine vinegar (optional)
Place the potatoes in a medium saucepan and add enough cold water to cover by about 2 inches. Bring to a boil over high heat, then lower the heat slightly to a gentle boil. Cook until the potatoes are tender, about 20-35 minutes.
Drain the potatoes and let them stand until cool enough to handle, but still quite warm.
Cut the potatoes into 1/2-inch slices and set them in a serving bowl. Scatter the onion, parsley and capers over the potatoes, then drizzle everything with the olive oil. Sprinkle with salt and pepper to taste.
Toss gently until all ingredients are well mixed. If desired, add vinegar and toss again. Serve immediately.
Serves six.
"Lidia's Italian-American Kitchen" by Lidia Matticchio Bastianich (2001 Knopf, $35)