Kale and collard greens make a flavorful team in this stir-fry dish. This tasty and healthy side dish combines collard greens and kale and includes olive oil, garlic, salt, black pepper, and lemon juice to season it and give it that tang. Make sure the greens are well washed. Collard greens, in particular, must be rinsed in several changes of water to ensure there is no grit still clinging to the leaves. Just fill the sink or a large bowl or dishpan with water and swish them around. Refill and repeat until you don't feel any bits of sand in the bottom of the sink or container.