Thoroughly wash the beet tops with cold water to remove any dirt and debris
Separate the stems from the beet leaves
Cut the stems into one-inch pieces and roughly chop the leaves
Put the stems into a skillet or wok and add enough water to cover them. Bring to a boil over medium-high heat, then reduce the heat, cover and simmer until tender, (About 5 minutes)
Drain the stems into a colander and set aside
Add the oil to the pan and heat over medium heat until a drop of water thrown in sizzles
Add garlic, salt, pepper and red pepper flakes
Cook, stirring for about a minute, until fragrant
Add the beet leaves and, using thongs, toss until the leaves are coated in the oil and spices. Continue to toss until the leaves are just starting to wilt.
Squeeze the juice of half the lemon over the leaves. Add the lemon zest, and toss to coat.
Remove from heat and serve immediately with the remaining half lemon, sliced.
Notes
Trim greens and their stems from beets right away to extend the storage life of both the beets and the greens. Beets will keep for quite a while in the fridge, up to a month, while greens should be used within 3-5 days.An easy way to wash beet greens: fill a large bowl with cold water, add the greens and swirl them around to remove any dirt or debris.