This is an old favorite from the excess of the nineties that I have lightened and brightened by cutting the butter and cheese, and by adding grapes roasted in a balsamic vinaigrette as a counterpoint to what is still a rich dish - like a grown up mac & cheese. The roasted grapes are adapted from a Southern Living bruschetta recipe. —chezjewels
Preheat the oven to 425 for the grapes and start the water on to boil for the pasta. Toss the grapes with the ingredients above, and spread on a rimmed baking sheet. Roast the grapes for about 15 - 20 minutes until soft and the juice is syrupy. The juice can burn quickly so it's good to keep an eye on it.
While the grapes roast, prepare the pasta.
For the pasta
Cook pasta in boiling water until just tender, but still with a firm bite.
While the pasta cooks, melt butter in a large skillet or sauté pan over low heat. Add Gorgonzola, stirring until smooth. Add half-and-half, Calvados, tomato paste, and most of the chopped pistachios, reserving some for garnish.
As soon as the pasta is barely al dente, drain it and stir the drained pasta into the Gorgonzola sauce.
Serve garnished with the remaining chopped nuts, snipped chives, and the roasted grapes on the side.