MASHED POTATOES WITH GREENS

Steps:

• Combine ham hock and 4 cups cold water in large saucepan; bring to boil. Reduce heat to medium-low, cover and simmer until ham is tender, about 45 minutes. Transfer hock to plate; cool. Remove meat from bone; chop meat.
• If necessary, boil ham broth until reduced to 3 cups. Add kale stems. Cover and simmer over medium heat 10 minutes. Add kale leaves. Cover and simmer 5 minutes. Add mustard greens; cover and simmer until all greens are tender, occasionally submerging greens in broth, about 20 minutes. Uncover; simmer until broth is reduced almost to glaze, about 10 minutes longer. Season with salt and pepper.
• Cook potatoes in large pot of boiling salted water until tender, about 30 minutes. Drain potatoes, reserving 1/4 cup cooking liquid. Return potatoes and reserved 1/4 cup cooking liquid to pot. Add butter and 3/4 cup whole milk. Mash potatoes until almost smooth, adding more milk if dry. Season potatoes to taste with salt and pepper.
• Spoon potatoes into large bowl. Make well in center of potatoes; spoon greens into well. Sprinkle with chopped ham and green onions and serve.