In her Essential Cuisines of Mexico, Diana Kennedy has a good recipe called Nopales al Vapor (page 208). Instead of boiling or grilling, you pan fry with onions, garlic and chiles and finish with epazote.
I really liked this method. The epazote isn't as strong as you'd think and gives the dish and extra little something.
Not being able to leave well enough alone, I added some left over beans without their broth and let the mixture cook a little more before making a really dreamy taco.
I know some people don't care but I get such a kick out of foraging my own yard for good food.