This ultrasimple soup requires little more than a couple of cans of black beans, some onion and a bit of cumin. A topping of fried tortillas (or store-bought chips) adds crunch.
Vegetable oil, for frying
3 6-inch corn tortillas, cut into narrow wedges
1 onion, cut into 1/4-inch dice
1 teaspoon ground cumin
2 15-ounce cans black beans
2 tablespoons chopped cilantro
Freshly ground pepper
How to Make It
In a medium saucepan, heat 1/2 inch of vegetable oil over moderately high heat until a deep-fry thermometer registers 350°. Add the tortillas and fry, stirring occasionally, until crisp and lightly golden, about 1 1/2 minutes. Using a slotted spoon, transfer the tortillas to paper towels to drain; season with salt.
In a medium soup pot, heat 2 tablespoons of the oil used to fry the tortillas. Add the onion and cook over moderate heat until softened, about 6 minutes. Add the cumin and cook for 1 minute. Add the beans and their liquid and 1 1/2 cups of water. Bring to a simmer and cook until slightly thickened, about 15 minutes. Stir in 1 tablespoon of the cilantro and season with salt and pepper. Ladle the soup into bowls and top with a few tortillas. Sprinkle with the remaining 1 tablespoon of cilantro and serve.