Add the pasta to a pot of salted water before grilling the tomatoes and put it on stove. Set the burner to a medium high flame to get the water boiling quickly. Pesto is best served as soon as it’s made and you’ll want the pasta finished and waiting for the sauce. Make sure you have plenty of water in the pot, you may need it to get the pesto to correct its consistency.
The first step is to prepared the tomatoes. Slice the tomatoes in quarters or fifths lengthwise and remove the locular ribs and seeds.
Carefully score the inside of the tomatoes widthwise so they will lay flat on the grill.
Preheat the grill to a high temperature and arrange the segments, skin down, in rows across the grill grates. The point is to get a good char on the skin and meat. If the grill is hot this should only take a few minutes.
Flip the tomatoes once the skin has a good color and grill the inside. By now the tomatoes will be getting very soft so you will have to be careful getting them off the grill without dropping them through the grates.
Take the pine nuts and garlic cloves and toast them lightly in a frying pan on your grill’s side burner over medium flame. If you don’t have a side burner, you can use your stove.
Keep the pine nuts and garlic moving in the pan so they don’t burn. Take them off the burner as soon as you see some color.
Combine the tomatoes, pine nuts, garlic, and parmesan in a food processor or mini chopper.
Blend the ingredients finely while slowly adding the olive oil, sugar, salt and pepper. The finished pesto will be a medium thick paste. At this moment the pesto is at its fullest flavor and should be served immediately.
The pasta should be taken off the burner when is slightly underdone or “al dente.” Drain the excess water from the pot but reserve it for the next step.
Transfer the hot pasta to a large bowl and add the pesto to the bowl. Using two wooden spoons mix the pesto into the pasta. If the pesto is too thick, add a few tablespoons of the pasta water. This water is rich with starch and salt and should help to coat the pasta thoroughly and create a wonderful sauce.
Once the pasta is thoroughly coated with pesto add the raisins (optional) and grate some additional parmesan over the bowl. Serve.
