Clean and cut up the cactus stems. Watch out for the sharp parts of the plant! You don't want to cut yourself. That could be quite painful. Next, measure how much oil you need. Heat the oil in a pan. Add the pieces of cactus. Add some salt and cover the pan to let the cactus cook. The cactus contains a strange liquid. Cook the cactus until all the liquid comes out and dries up. After that, the rest of the cactus stem can be eaten.