I recommend chard (a.k.a. Swiss chard, beets bred to produce a lot of greens instead of large roots). Chard is expensive and hard to find in shops because it ha

I recommend chard (a.k.a. Swiss chard, beets bred to produce a lot of greens instead of large roots). Chard is expensive and hard to find in shops because it has short shelf-life once harvested, and because you need to harvest individual leaves as it grows instead of cutting the whole plant at once. But it's easy to grow, and the drawbacks are no problem to a home gardener.