Bread in Soups

• Historically, bread has been too precious a food to waste. Europe and the Middle East have a rich heritage of dishes designed to use up leftover breads, using even the crumbs as an ingredient in meals. The English word "soup" itself provides an example. Cooks would place a thick slice of stale bread in a bowl, and ladle broth over it. That piece of bread, the "sop," eventually gave its name to the meal. French onion soup is one example that has survived to the present day.

Bread-Thickened Soups

• In other cases the bread was crumbled into the soup, or soaked in broth and then mashed to a paste in a mortar and pestle as the soup's thickener. Gazpacho, a signature Spanish soup, uses that technique. Breadcrumbs are incorporated into the broth made by mashing or pureeing fresh tomatoes, cucumbers and bell peppers, adding body to the watery vegetables. Portugal has a simple peasant soup made from just water, stale bread and quality olive oil. In Italy, bread and seasonal greens are simmered together to make a hearty rustic soup called ribollita.

Tortillas in the Bowl

• European-style yeast breads aren't the only ones that work as thickeners. Tortillas are just as adept at thickening broths, making a light soup or stew heartier and more satisfying. Chicken tortilla soup is one well-known example, though the technique can be used with any thin soup or brothy stew. The simplest way to use tortillas as a thickener is to cut them into strips, and add them to the bowl. As the soup or stew soaks into the tortillas, the remaining broth becomes thicker and more concentrated. Toasted flour tortillas or crisped corn tortillas can also be used as a garnish on top of the soup, and will also help soak up the broth.

Tortillas in the Pot

• Alternatively, you can add the tortillas to your pot during cooking. Flour tortillas can be used this way, though corn tortillas work better and are more traditional. Corn tortillas are made with nixtamalized or lime-treated corn, so they should be crisped in a small amount of oil before they're used. Otherwise, they add a sharp taste of lime to the finished soup. Crumble the crisped tortillas into your pot at least 30 minutes before the soup or stew is finished. The tortillas' starches will absorb liquid from the broth and swell, providing a thickening effect and a distinctive flavor to the soup.