Oyster Soup

This is a recipe I got out of a book about the life of Frida Kahlo, the Mexican artist, who was married to Diego Rivera a great Mexican muralist. This soup was served at their wedding and it is Diego's favorite. I alter it differently each time I make it but it is always flavorful and good. What I like to add is shrimp and scallops. Yummy. The part I have problems with is the tomato ingredient. It calls for 2 fresh tomatoes but in the photo in the book it looks like there are 6 tomatoes used; my soup never looks like the books photo, anyway.