Grab the entire leak and lay it parallel to you on your workspace. You are then going to cut the bottom piece off, where all of the roots are sticking out. Leaks are a root vegetable, so that area that you are cutting off lived in the ground for quite a bit! Next, you are going to cut all of the leafy stalk off. In order to find the top of the usable stalk, find the leafy greens and look closely at when it goes from a pale white color to a grainy green texture. Cut where the grainy green texture starts gaining more of the green pigment.
Once you have your usable stalk, start slicing the stalk from the bottom to the top in thin slices. Once you have all of your thin slices, throw them into a bowl with some water and move them around with your hand. You may see some of the dirt left from its growing process in the bowl. Grab the leaks with your hand and pour the water out then grab a paper towel and smush them down to get as much of the water out as you can.
Chop your spinach in a rough chop, ensuring that there are no large whole pieces of spinach. Take your spinach, leak, egg, cottage cheese, and crumbled feta cheese, and toss it into your prep bowl. Give it a little stir and make sure everything is well mixed and incorporated.