2. Using a mortar and pestle, pound the garlic to a paste with the cumin and 1/2 teaspoon of salt.
3. Transfer the bread mixture to a food processor along with the garlic paste, and process until completely smooth. Leave this mixture in the food processor while preparing the next step.
4. Chop the tomatoes, cucumbers, red and green peppers, and onion into medium dice. Place the vegetables in a bowl, stir in three large pinches of salt, and let stand for 15 minutes so that the tomatoes throw off some liquid.
5. Working in three batches, process the vegetable mixture in a food processor until as smooth as possible, adding a third of the olive oil to each batch. (The first batch will be processed with the bread mixture.) Transfer each finished batch to a sieve set over a large bowl.
6. Pass the gazpacho through a sieve, pressing on it with the back of a wooden spoon. Whisk in the remaining 3 tablespoons vinegar and the water. Adjust salt to taste. Chill the gazpacho for at least 3 hours before serving. (If making the gazpacho a day ahead, add the garlic 2 to 3 hours before serving, lest it overwhelm the other flavors.) Serve in glass bowls or wine glasses, with the suggested garnishes.
Sandor Katz lives to ferment; it’s his life’s work. The author of The Art of Fermentation shares how to make kombucha at home.