Place the tomatoes, garlic, onion and water in a blender or food processor. Puree until smooth.
Heat the oil in a large soup pot over medium-high heat. When the oil is hot, but not smoking, add the pasta, stirring continuously. As you fry the pasta, it will change in color from a deep white to a deep brown. Take care not to burn it! You want to cook it until it smells toasty, but not bitter like burned toast, about 2 to 3 minutes.
Pour the tomato puree over the pasta, sprinkle in the salt, and stir. Be careful, as the puree will want to jump all over your burners, it’s a good idea to cover it partially with a lid. Let the tomato base cook and thicken for about 6 minutes, stirring often, until it becomes a deeper red and has thickened to the consistency of a thick puree. Keep on stirring, so the pasta doesn’t stick to the bottom of the pot. You will see the base of the pot as you stir, but the sauce will not be dried out. Cooking the tomato puree to this point will give the soup a really nice depth of flavor.
Pour in the broth, stir, and when it comes to a boil, reduce the heat to medium and simmer for another 10 minutes. Taste for seasoning and serve.