Pasta with Kielbasa and Swiss Chard

Ingredients

• 2  garlic cloves finely chopped
• 0.5 pound kielbasa quartered
• 2 tablespoons olive oil 
• 0.5 cup parmigiano-reggiano plus additional finely grated for serving
• 0.8 pound penne pasta 
• 0.3 teaspoon red-pepper flakes dried hot
• 0.5 teaspoon salt 
• 0.8 pound swiss chard red (preferably ; from 1 bunch)
• 0.5 cup water 

Equipment

• bowl
• pot
• slotted spoon
• colander

Directions

1. Cut out center ribs and stems from chard, then thoroughly wash, along with leaves, in several changes of cold water.
2. Cut ribs and stems crosswise into 1/4-inch-thick pieces and coarsely chop leaves.
3. Cook kielbasa in oil in a 5-quart heavy pot over moderately high heat, stirring occasionally, until golden, 2 to 3 minutes.
4. 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.
5. Add garlic and cook, stirring, 1 minute.
6. Add chard leaves, water, and red-pepper flakes and simmer, partially covered, until chard stems are tender, about 5 minutes.
7. Remove lid and stir in kielbasa.
8. 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.
9. 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.