Preparation Cook pancetta in a 12-inch heavy skillet over moderately high heat, stirring frequently, until browned, 5 to 6 minutes. Transfer pancetta with a slotted spoon to paper towels to drain. Reduce heat to moderate, then add butter to fat remaining in skillet and, when foam subsides, cook parsnips, stirring occasionally, until tender and lightly browned, about 12 to 14 minutes. Remove from heat. Meanwhile, cook pasta in a large pot of salted boiling water until al dente. Reserve 2 cups pasta-cooking water, then drain pasta. Add pasta and 1 1/2 cups reserved cooking water to parsnips. Stir in pancetta and parsley and toss over moderately high heat 1 minute, adding more pasta-cooking water if necessary for sauce to lightly coat pasta. Season with salt and pepper.
Preparation Cook pancetta in a 12-inch heavy skillet over moderately high heat, stirring frequently, until browned, 5 to 6 minutes. Transfer pancetta with a slotted spoon to paper towels to drain. Reduce heat to moderate, then add butter to fat remaining in skillet and, when foam subsides, cook parsnips, stirring occasionally, until tender and lightly browned, about 12 to 14 minutes. Remove from heat. Meanwhile, cook pasta in a large pot of salted boiling water until al dente. Reserve 2 cups pasta-cooking water, then drain pasta. Add pasta and 1 1/2 cups reserved cooking water to parsnips. Stir in pancetta and parsley and toss over moderately high heat 1 minute, adding more pasta-cooking water if necessary for sauce to lightly coat pasta. Season with salt and pepper.