Place them on a baking tray and cook for about 50-60 minutes until tender, then remove them from the oven.
As the spuds are baking, get started on the kale leaves. Wash them and remove the stems. Chop up the leaves.
Cook in a pot of rapidly boiling water for 2 minutes, then drain and run under cold water to stop cooking process. When done, put it to one side.
Slice potatoes lengthwise, and scoop the insides out into a blender, leaving a good 1/4 inch of potato flesh still attached to the potato skin (otherwise, your potato might fall apart) - If you don't have a blender, you can mash it up with a fork.
Add the broccoli, kale, and milk to the blender and blend until smooth. Season to taste with salt and pepper.
Scoop the pureed broccoli-kale-potato mixture back into the potato skins. Sprinkle with the grated cheddar cheese, return to the baking sheet, and bake for another 10 minutes.
Cook until the cheese turns a golden brown and then get it down your neck.