Salsa de Nopales Recipe

Bring one gallon of water to a boil in a large pot. Add baking soda and salt. Cut the nopales across the grain into 1/4-inch strips, then cut these into 1/2-inch pieces. Add the nopales to the boiling water. When they are soft and still green, after about 15 minutes (do not cook them too long or they will turn brown), drain and run cold water over them, while still in the pot, to stop the cooking process. This step (along with cooking in copper) retains the green color so important to the dish. Rinse the nopales in a strainer, then shake out as much moisture as possible. Put the nopales in a bowl and add the tomatoes, chiles, onion, cilantro, salt, and pepper. Mix to combine. Serve at room temperature.