Steven Wagner, an Italian-born radicchio enthusiast, gave us this recipe.

SERVES 4

2 heads chioggia or treviso radicchio
1 medium yellow onion, peeled and chopped
1/4 lb. pancetta or slab bacon, julienned
3 tbsp. extra-virgin olive oil
Salt and freshly ground black pepper
1 lb. pappardelle
Freshly grated parmigiano-reggiano

1. Core, then julienne, chioggia or treviso radicchio.

2. Heat oil in a large skillet over medium heat. Add pancetta and brown, stirring occasionally, for 5–10 minutes. Reduce heat to medium-low and add onions. Season with salt and pepper and cook, stirring occasionally, until onions are golden, about 30 minutes.

3. Meanwhile, cook pappardelle in a large pot of salted water until al dente, about 8 minutes. Drain pasta, reserving 1/2 cup cooking water. Add radicchio to onions and pancetta and cook, stirring, until radicchio is wilted, about 3 minutes. Add pasta and reserved cooking water, mix well, season with salt and pepper, and serve topped with freshly grated parmigiano-reggiano.