Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
4         tablespoons   olive oil
2         cups          chopped onions
2         pounds        gold potatoes peeled cut in 1-inch pieces
8         cups or more  water
1/2       teaspoon      crushed dried red pepper
4                       garlic cloves -- minced
1         bunch         mustard greens leaves - trimmed coarsely chopped
10        oz. pkg       fresh spinach -- stems trimmed
                        sour cream

Preparation:

Heat 2 tablespoons oil in heavy pot over medium heat. Add onions and saute until tender and golden, about 8 minutes. Add potatoes and saute 3 minutes. Add 8 cups water and crushed red pepper. bring to boil, Reduce heat. Simmer until potatoes are tender, about 20 minutes. Meanwhile, heat remaining 2 tablespoons oil in another heavy large pot over medium heat. Add garlic; saute until fragrant, about 1 minute. Add mustard greens and all but 1 cup spinach leaves; Saute until wilted, 3 minutes. Add sauted greens to potato mixture. Working in batches, puree soup in blender until smooth(Can be prepared 1 day ahead. Cool. Cover and refrigerate.) Return soup to pot. Bring to simmer, thinning with more water if desired. Season soup to taste with salt and pepper. Cut remaining 1 cup spinach leaves into 1/2-inch wide slices. Ladle soup into bowls. Add dollop dour cream in each bowl. Garnish soup with sliced spinach leaves and serve.