This recipe is a great example of what people have done with their greens for generations.  The leftover liquid is great stock for soup or dunking cornbread.

1 ham hock
1 quart water
2 pounds mustard greens
2 pounds turnip greens
Salt and pepper

Boil meat in water about half an hour. Wash greens. Add leaves to pot and cook for 25 minute or until tender. Season.