Remove and discard kale stems. Stuff the kale leaves into a medium pot and add ½ C water. Cook until the kale just wilts, about 7 minutes. Drain and cool the cooled kale, then squeeze out the excess water. Roughly chop the kale and set aside. Preheat oven to 425 F. Generously butter the bottom of a large, shallow baking dish. Spread half of the potato slices onto the bottom of the dish. Spread on all of the kale and garlic plus half of the cheese, butter, salt, & pepper. Top with the remaining potato slices, cheese, butter, salt, & pepper. Carefully pour in the milk and gently shake the dish to distribute. Bake 50 minutes or until potatoes are tender and the top is nicely browned.