Gnocchi with Radicchio, Pancetta, Pine Nuts, and Rosemary

Recipe by Pasta da Pulcinella for Bon Appetit

1 1/2 pounds russet potatoes, scrubbed
1 cup all purpose flour plus additional (for sprinkling)
1 large egg yolk
1/2 teaspoon salt
9 ounces thinly sliced pancetta (Italian bacon), coarsely chopped
1/2 cup chopped shallots (about 2 large)
3 garlic cloves, chopped
2 tablespoons olive oil
1 cup sliced radicchio
2 tablespoons chopped fresh Italian parsley, divided
1 teaspoon minced fresh rosemary
2 tablespoons finely grated Parmesan cheese plus additional (for passing)
1 tablespoon pine nuts, toasted

Place unpeeled potatoes in large saucepan of water. Bring to boil. Continue boiling until tender, 35 to 45 minutes, depending on size of potatoes. Drain; let stand until cool enough to touch, about 10 minutes. Using knife and fingertips, peel potatoes. Cut potatoes into 2-inch pieces; press through potato ricer or food mill into large bowl. Cool. Add 1 cup flour, egg yolk, and salt; mix to blend, then transfer to floured surface and knead briefly to form dough.

Sprinkle rimmed baking sheet with flour. Divide dough into 4 pieces. Roll out 1 piece into 3/4-inch-diameter log. Cut log crosswise into 1-inch gnocchi. Roll back of fork along gnocchi, forming indentations along 1 side. Place gnocchi on sheet. Repeat with remaining dough. DO AHEAD Can be made 1 day ahead. Cover; chill.

Working in batches, add gnocchi to large pot of boiling salted water; cook until gnocchi float to surface, then boil until cooked through, about 3 minutes longer. Using slotted spoon, transfer gnocchi to same baking sheet.

Meanwhile, heat large skillet over medium heat. Add pancetta; sauté until crisp and golden. Add shallots and garlic and sauté 1 minute, stirring constantly.

Add oil to skillet. Add radicchio, 1 tablespoon parsley, rosemary, and gnocchi and toss until radicchio wilts, about 2 minutes. Season with salt and pepper. Transfer gnocchi mixture to platter. Sprinkle with 2 tablespoons cheese, toasted pine nuts, and remaining 1 tablespoon parsley. Serve, passing additional cheese alongside.