This is from the "Vegetarian Appetizers" cookbook. The picture looked so fabulous that I just had to try it. DH and the other guests just gobbled these up. The pesto is pretty tasty! You will have to guage the olive oil based upon how you like your pesto. The yield on this is dependent upon the size of the tomatoes used and how you cut them. This yield assumes the tomato only has the top cut off, not in half.