Heat the butter in a large, deep skillet over medium-high heat, about 2 minutes.
Add the garlic and cook it for 30 seconds.
Add the kale in batches, as shown in the video below.
Stir-fry until the kale is tender and slightly wilted, about 5 minutes.
Stir in the salt, black pepper, and lemon juice.
Make sure to avoid overcooking the kale. You want it to still have some "bite," just like al-dente pasta. You don't want it mushy and limp.You can keep the leftovers in the fridge, in a sealed container, for 3-4 days. They keep pretty well, although they won't be as good as when freshly made. Reheat the leftovers gently, covered, in the microwave on 50% power.