Heat the oven to 350ºF.
Cut the kale into thin ribbons. Sprinkle with salt and massage several minutes, until the kale begin to soften. Set aside.
Crack the eggs into a large measuring cup. Add the milk, if using, and season with salt and pepper. Whisk well to combine.
Spray a muffin tin with nonstick spray or oil. Pour the eggs into nine of the muffin cups, filling each 3/4 of the way full. Add some ham, kale, parsley, and chives to each cup. Use a fork to stir gently, so that the kale is submerged.
Bake for 20-25 minutes, or until the tops of the egg cups are set. Let cool slightly, then remove the eggs from the pan. Serve immediately or refrigerate for later.