I have found that legume crops self sow easily when scattered on wood chip mulch fresh or partially composted. What else grows in the wood chips will depend on location, soil, and depth and level of decay of wood chips or mulch. Try different plants suitable for your area and figure out what works. Some plants have a hard time reaching the soil through a thick mulch but legumes can grow in the mulch no problem.
@ Susan B
Google says you are in zone 9b if so you can grow pigeon pea, okra, roselle, potatoes, yams, onion, peanuts, (cow pea, lab lab for ground cover), pumpkins, and a whole lot of other things fairly easily in the mulch/wood chips. Your area is a bit dryer than mine but most of these plants love sun and grow easily in mulch. Give them a try.