Preparation Cut out center ribs and stems from chard, then thoroughly wash, along with leaves, in several changes of cold water. Cut ribs and stems crosswise into 1/4-inch-thick pieces and coarsely chop leaves. Cook kielbasa in oil in a 5-quart heavy pot over moderately high heat, stirring occasionally, until golden, 2 to 3 minutes. Transfer with a slotted spoon to a bowl. Cook chard ribs and stems with salt in fat remaining in pot over moderate heat, stirring occasionally, 3 minutes. Add garlic and cook, stirring, 1 minute. Add chard leaves, water, and red-pepper flakes and simmer, partially covered, until chard stems are tender, about 5 minutes. Remove lid and stir in kielbasa. Cook pasta in a large pot of boiling salted water until al dente, then reserve 1/2 cup pasta-cooking water and drain pasta in a colander. Add pasta to chard mixture with cheese and salt to taste and toss until combined well. Thin with some of reserved pasta water if necessary.
Preparation Cut out center ribs and stems from chard, then thoroughly wash, along with leaves, in several changes of cold water. Cut ribs and stems crosswise into 1/4-inch-thick pieces and coarsely chop leaves. Cook kielbasa in oil in a 5-quart heavy pot over moderately high heat, stirring occasionally, until golden, 2 to 3 minutes. Transfer with a slotted spoon to a bowl. Cook chard ribs and stems with salt in fat remaining in pot over moderate heat, stirring occasionally, 3 minutes. Add garlic and cook, stirring, 1 minute. Add chard leaves, water, and red-pepper flakes and simmer, partially covered, until chard stems are tender, about 5 minutes. Remove lid and stir in kielbasa. Cook pasta in a large pot of boiling salted water until al dente, then reserve 1/2 cup pasta-cooking water and drain pasta in a colander. Add pasta to chard mixture with cheese and salt to taste and toss until combined well. Thin with some of reserved pasta water if necessary.