- ½ cup red wine vinegar
- ½ cup cold water
- ¼ cup sugar
- ¼ cup salt, plus more to taste
- 1 large red onion, halved lengthwise and thinly sliced
- 12 ounces pancetta, sliced paper-thin
- 4 heads radicchio, quartered
- Freshly ground black pepper
- 1 cup balsamic vinegar
- 1 tablespoon extra virgin olive oil
- 1 teaspoon fresh rosemary leaves
- In a small bowl, combine the red wine vinegar, water, sugar, and salt. Add the onion and let stand for 1 hour.
- Unroll the slices of pancetta and wrap 2 pieces of pancetta around each radicchio quarter. Set aside.
- Heat a 10- to 12-inch nonstick sauté pan over medium heat for 1 minute. Gently place the radicchio in the pan and cook, turning frequently with tongs, until the pancetta is browned and crisp, 6 to 8 minutes. Transfer to a plate. Sprinkle with salt and pepper, cover with foil, and keep in a warm place.
- Drain any fat from the pan, and add the balsamic vinegar and olive oil. Bring to a boil and reduce by half. Remove from the heat.
- Drain the onions, discarding the liquid, and arrange one-quarter of the onions in a small pile in the center of each plate. Lean the warm radicchio pieces up against the onions like a teepee, and spoon about 1 teaspoon balsamic sauce over each piece. Sprinkle with rosemary and serve immediately.