Sicilian Pesto

This picture is so reminiscent of Sicily to me.  A narrow walkway in a 13th Century town typifies so many places on the island.  The ancient stone walls seem to whisper to each other they are so close and have been sharing the same small space for so long.
As old as the walls are, the tastes and aromas of Sicily is even older.  Herbs growing wild on the roadside combined with the nuts and olive oil that are produced in great quantity lend themselves to the exotic and delicious pesto that seems as far away in style and taste as the Ligurian version most of us are used to.  But I actually like this as a break from the Pesto Genovese which has found its way into everything from pasta, to chicken breasts to pizzas and beyond.  I find the Sicilian version much more rustic and interesting.
This recipe comes from the book, La Cucina Siciliana di Gangivecchio by Wanda and Giovanna Thornebenne.  I like this because the "kick" in this recipe is produced by the addition of arugula instead of chili flakes.

Spaghetti with Arugula Pesto 

4 cups loosely packed fresh arugula, coarsely chopped
2 cloves garlic
1/2 cup walnuts
1/2 cup olive oil
4 medium-sized tomatoes, peeled
Salt and freshly ground pepper
1 pound spaghetti
1 tablespoon butter
Parmesan or pecorino cheese

Place the arugula, garlic, walnuts, olive oil and one of the tomatoes (chopped) in the bowl of a food processor and process to desired consistency.  Season with salt and pepper to taste and set aside.
Dice remaining  tomatoes.
Mix a little sauce and the butter in the bowl in which the pasta will be served.
Cook spaghetti in boiling salted water and drain reserving one cup of the cooking liquid.
Place pasta, half the sauce and half the diced tomatoes in the serving bowl and toss gently.
Add the rest of the sauce and tomatoes and toss again using a some of the cooking liquid to loosen the sauce if needed.
Serve and pass cheese.