If your nopales ever came out “slimy,” it wasn’t you — it was the cook time. Cooked just enough and drained well, they come out firm and clean.
Put them in water with a chunk of onion and a pinch of salt; boil 10–12 minutes, until they turn from bright to dull green.
The draining trick
Add a couple of tomatillos or a teaspoon of baking soda to cut the slime; drain and rinse under cold water. The drier, the better.
This content is educational and is not a substitute for medical advice. Consult your health professional.