I like getting wheat berries at the health food store, like Whole Foods. They are about 1.29 a pound right now in the scoop your own section. Plant in various little pots every few days so you can rotate them in. They sprout into wheatgrass fairly quickly and are yummy good. Babies will act like little adults grazing, so cute. I also like nasturtiums because they are also fast and easy and viney. Totally edible, for people too. Those flowers look awesome in salads. Make sure when buying seeds to plant, that they are not coated with fertilizer, some are these days. Oh, and Johnny Jump Ups. Those are easy and edible. I got the seeds at Home Depot. You can also get arugula seeds. And they have lettuce mixes also. In Feb or so you can plant California poppies for them.
Here is a fun link I think you will like. Now, it is for leopard tortoises, but as I looked at the plants, they are almost all good for gopherus also. I like pretty pictures and this man has done a good job with this. I like how he has what part of the plant is edible for tortoises. And I notice that he keeps adding to it ... more variety ... hope you like it, too. : )