Since I have a large backyard (for Berkeley) I like to try to grow a lot of my own food. Prickly pear/nopales/Opuntia. It is quite easy to grow and can become quite weedy in warm climates. I’m a fan of the juice from the ripened fruit, or tuna, but an even bigger fan of the paddles. They are great grilled–just remove the spines with a knife and grill until they show some blackening. They have a lemony tang and make great tacos with some queso fresca or an addition to salad.
I broke off this paddle from a neighbor’s plant (with permission) a couple months ago. They re-root easily, just make sure to let the broken edge dry for a day or two. Then place in a pot and water whenever the soil is dry. Mine rooted fairly quickly, and once it started budding I decided it was time to put it in a bigger pot.