The last time I purchased nopales it was in a very convenient form with spines removed and pre-chopped, however, I was disappointed because they did not cook up tender but were very tough and crunchy.
This time I bought whole cactus pads, still convenient with the thorns pre-removed. I borrowed a skiving tool from my leather studio to remove more of the skin to my satisfaction. It worked like a charm, much better than a straight bladed vegetable peeler or a knife.
I sliced the peeled cactus into thin strips and put them in a pot of cold water with chunks of onion, a clove of garlic, cilantro, a large (three finger) pinch of whole cumin seeds and a generous amount of kosher salt. This was brought to a boil and left to simmer for about 30 minutes until tender.
The tender cactus was then tipped into a colander and rinsed under cold water to remove the slime exuded by the cactus.
At this point the nopalitos could be used in any number of ways. They are great on pizza or nachos. I went on to sauté the rinsed cactus starting with chopped onion, jalapeño, cumin seeds and salt.
Cactus is frequently served just like this as a side dish.
I decided to use some of the nopalitos in an egg dish and put the rest in the refrigerator to use later.