In a large saucepan, boil cabbage until tender; remove and chop or blend well. Set aside and keep warm. Boil potatoes until tender. Remove from heat and drain.
2
Chop leeks, green parts as well as white, and simmer them in just enough milk to cover, until they are soft.
3
Season and mash potatoes well. Stir in cooked leeks and milk. Blend in the kale or cabbage and heat until the whole is a pale green fluff. Make a well in the center and pour in the melted butter. Mix well.