This dish appears in many variations on the Zuni menu. At times it might include, among other things, squab or duck livers and employ dry marsala or cognac instead of sherry. The pickled onions are good with grilled birds or fried fish, too, and give extra crunch to a BLT.
FOR THE PICKLED ONIONS:
1 1/4 cups champagne vinegar or white wine vinegar
2 heaping tbsp. sugar
2 bay leaves
1 small dried red chile
5 black peppercorns
A few pinches salt
6 small yellow onions
(about I lb.), peeled, sliced into 1/4"–1/2"-thick
rings and separated, ends discarded
FOR THE SALAD:
2 oz. sliced bacon, cut crosswise into about 1" pieces
2–3 tbsp. extra-virgin olive oil
4 oz. chicken livers, trimmed, rinsed, and patted dry
Salt and freshly cracked black pepper
2 tbsp. whole zante or 6 halved seedless red flame grapes
2 small handfuls watercress
1/4 tsp. sherry vinegar
3 tbsp. oloroso sherry
1. For the pickled onions: Combine 1 1/4 cups water, vinegar, sugar, bay leaves, chile (broken in half if you like a spicier pickle), peppercorns, and salt in a small saucepan, bring to a simmer over medium heat, and add onions. Gently stir the crowded onions as the brine returns to a simmer, then simmer them for 45 seconds. Pour onions and brine into clean jars and allow to cool. Tightly cover and store in the refrigerator for at least 1 day and up to 6 months.
2. For the salad: Put bacon into a medium skillet and cook over medium heat until just crisp. Set bacon aside, reserving rendered fat in skillet. Increase heat to medium-high and add 1 1/2 tbsp. of the oil. Add livers, season to taste with salt and pepper, and cook until they are browned on each side and faintly rosy on the inside, 1–1 1/2 minutes per side. Stir in bacon, grapes, and 8–10 ringlets of the pickled onions (save remaining onions for another use).
3. Toss watercress with vinegar and 1/4 tsp. of the oil, then divide between 2 plates. Spoon half the livers, bacon, grapes, and onions onto each plate. Deglaze skillet with sherry over medium-high heat, stirring constantly, then add remaining oil, swirling skillet over the heat. Spoon sauce over livers and salad and serve immediately.