In a large skillet, gently heat your olive oil over medium heat. Add the onion and allow it to cook until softened, about 5 minutes or so. Add the kale and sprinkle it with salt. Use a spatula to move it around the pan, mixing the kale and onions together. Add the 3 tablespoons of water and cover the skillet with a lid. Allow the kale to steam until it is tender and bright green but not totally wilted, just a few minutes.
Meanwhile, add a little oil or butter to a separate skillet (I like cast iron for eggs, but any pan will be fine). Heat the oil or butter (you need just enough to cover the pan) until it is hot, then add your eggs to the hot pan. Lower the heat to low and cook a few minutes, until the egg whites and yolks reach your desired consistency. Season with salt and pepper, if desired. I often add smoked paprika to the eggs, which is also excellent.
Once the kale is cooked, stir in the lemon juice and top with lemon zest. Put the kale on a plate and top with the fried eggs. Enjoy!