By Joyce Goldstein
A study in crunch—the toasted hazelnuts, peppery pancetta, and sweet red onions all add a wonderful texture that contrasts beautifully with the silkiness of the liver.
Heat ¼ cup oil in a large sauté pan over medium heat. Add the onions and cook until tender, 7 to 10 minutes; remove from the pan and set aside.
Heat 2 tablespoons oil in the same pan over medium hea