Pasta with Rapini, Gorgonzola and Walnuts

Serves 4

1/4 cup extra-virgin olive oil

1 red onion, thinly sliced

1/2 teaspoon each salt and pepper

2 cloves garlic, minced

2 teaspoons red wine vinegar

1 bunch rapini (12 oz/375 g)

12 oz (375 g) bucatini or other long pasta

3 oz (90 g) Gorgonzola cheese, crumbled

1 cup toasted walnut pieces

In skillet, heat half of the oil over medium-low heat; cook onion and half each of the salt and pepper, stirring occasionally, until lightly caramelized, about 15 minutes.  Stir in garlic; cook for 5 minutes.  Stir in vinegar.

Meanwhile, trim 1/2 inch (1 cm) from rapini stems; cut rapini in half.  In large pot of boiling salted water, cook rapini until tender, about 2 minutes; drain and stir into onion mixture.

Meanwhile, in separate saucepan of boiling salted water, cook pasta until al dente, about 8 minutes.  Drain, reserving 1/3 cup of the cooking liquid.  Return pasta to pot.

Stir in onion mixture, cheese and remaining oil, salt and pepper.  Pour in reserved liquid if necessary to moisten.  Sprinkle with walnuts.