Chef Note: This is a great sauce for pasta salad because it's delicious at room temperature. You could also slather it on bruschetta, grilled fish or chicken. Or make a brunch dish by topping a thick slice of toast with proscuitto, a poached egg and a little of this summer pesto. In summer, when you can get your hands on vine-ripe tomatoes, you don't even need to peel them. To intensify the flavor, you can add a few oven-dried tomatoes. The pesto keeps several days in a tightly sealed container in the refrigerator.
Combine the tomatoes, garlic, basil, olive oil, vinegar, and salt and pepper, to taste, in a blender and puree until smooth. Add the cheese and blend briefly just to mix. Transfer to a bowl and adjust the seasoning.