1. In a large pot, bring 2 quarts of very hot tap water to a boil over high heat. When water boils, sprinkle in 2 tsp. salt and add macaroni. Cook until just al dente, about 6 to 8 minutes. Drain and return pasta to pot.
2. While pasta cooks, heat oil in a large nonstick skillet over medium-high heat. Finely chop onion and add to pan. Saute, stirring occasionally, while you prepare the chard.
3. Rinse chard well, trim ends, and shake excess water off the leaves. Cut leaves off stems and set aside. Finely dice stems and stir into onions. Cut the leaves in half lengthwise, then thinly slice widthwise. Add leaves to onions and stir to mix. Pan will appear full, but the chard will cook down. Saute 2 minutes.
4. Rinse and drain kidney beans, then add to chard. Reduce heat to medium and cover pan to steam chard until tender, about 5 minutes.
5. Finely grate cheese. Add about 1/4 cup at a time to the drained macaroni, stirring after each addition. The cheese should melt into the pasta. Stir in vinegar and pepper. Mix well, making sure there are no clumps of unmelted cheese.
6. Uncover the chard and stir. It should be cooked through and tender. Add chard mixture to the pasta, stirring well to distribute. Divide among 4 bowls and serve immediately.
Source: fresh Magazine May, June 2010