Kale with Pancetta & Marjoram

• 3 Tbs. extra-virgin olive oil
• 3 oz. pancetta, cut into 1/4-inch dice
• 1 large yellow onion (12 oz. ), halved lengthwise, trimmed, and thinly sliced lengthwise (about 3 cups)
• Freshly ground black pepper
• 2 large cloves garlic, chopped
• 2-1/2 lb. kale (about 2 bunches), stemmed, leaves torn into large pieces, rinsed well, and drained but not dried
• 2 tsp. chopped fresh marjoram
• 1/8 to 1/4 tsp. crushed red pepper flakes
• Kosher salt
• 1 tsp. red-wine vinegar

Heat 2 Tbs. of the oil in a wide 8-quart pot with a lid over medium heat until shimmering. Add the pancetta and cook, stirring occasionally, until golden, 4 to 5 minutes. Add the onion and a few generous grinds of pepper and cook, stirring occasionally, until softened and beginning to brown around the edges, 5 to 7 minutes. Add the garlic and cook until the onion is lightly caramelized, 4 to 6 minutes.

Pack the kale into the pot and sprinkle with the marjoram, red pepper fl akes, and 1/2 tsp. salt. Cover the kale and let it wilt for 1 minute. Toss the kale and onions together with tongs, cover, and cook, removing the lid to toss occasionally, until just tender, about 10 minutes (taste a piece to check). Toss with the vinegar, the remaining tablespoon oil and, if necessary, additional salt and pepper to taste.