1. Cut the chard stems crosswise 1/2 inch thick. Cut the leaves into 1/2-inch-thick strips. In a large saucepan of boiling water, cook the stems until almost tender, about 3 minutes. Using a slotted spoon, transfer the stems to a plate. Add the chard leaves to the boiling water and cook until tender, about 2 minutes. Drain the leaves and let cool, then coarsely chop.
2. Cook the malloreddus in a large pot of boiling salted water, stirring occasionally, until al dente; drain.
3. In a large skillet, melt the butter in 2 tablespoons of the olive oil. Add the garlic and lemon zest and cook over low heat until the garlic is golden, about 3 minutes. Add the chard stems and leaves and season with salt and pepper. Add the malloreddus to the skillet and toss until hot. Transfer the pasta to a large, warmed bowl, scatter the Gorgonzola on top and drizzle with the remaining 1/2 tablespoon of olive oil. Using 2 large spoons, toss briefly to melt the cheese slightly; serve at once.
Notes: Malloreddus is a small Sardinian ridged pasta that is often flavored with saffron. It can be white, bright yellow or tricolored, and it pairs beautifully with the multicolored chard. Malloreddus is available by mail order from Dean & DeLuca, 800-999-0306.