Fresh cactus pads are available year-found in Mexican markets and some grocery stores. Choose small or medium-size firm pads. They should not be wrinkled, soggy or too soft. If you are growing prickly pear cactuses in your garden, the pads are at their best in the spring. You can eat the pads of any variety of prickly pear.
Harvest the nopal cactus when the individual leaf is young and fresh. The leaves will generally be hand sized, they must have a glossy green sheen and be of minimum thickness, about 3/8 inch thick. When the leaf has grown too thick and has lost its sheen, it will be pithy inside. The leaves are best separated from the main plant with a knife by slicing through the leaf approximately 1 inch above the junction point from which it grows from the leaf below. The stub left on the older mature leaf below will grow a new leaf from its surface, generally the next year.
The harvested leaf must now be rid of spines if any, glochids if any (the hair-like tiny spines that still get in the skin), or the green nubs that grow on the areoles of the spineless varieties. These green nubs will remove easily with a green scrubbing pad or cloth. The spines and glochids must be cut off with a knife by slicing through the skin under the areole from which the spines and glochids grow, this process is known as "skinning." OR Use tweezers to remove the spines. Use a sharp paring knife or vegetable peeler to remove the bases. Cut them into pieces about 1/4 inch wide by 2 inches long. Boil them in salted water for about 15 minutes. To eliminate the "baba" (Spanish word for the slimy fluid), boil the nopalitos with a raw onion or two cloves garlic, which absorb the baba. Cool. They are now ready to use in salads.
If you have tomatillo husks, add them to the water to eliminate the okra-like sliminess that nopales can have.
If using canned nopales, rinse the vinegary solution from them before using. It is however, not recommended that you ever use canned nopales.
Once the leaf is safe to handle it is generally sliced french-fry style, or diced into 3/8 inch dimensions. The leaves are then most often boiled for approximately 10 minutes, and then mixed into some other food that has been already cooked, the ingredients are then cooked some more to blend flavors and eaten.