Rating: Untried
Mustard greens, increasingly common in supermarkets today, cook as quickly as fresh spinach. Their assertive taste is terrific here in a warming winter soup.
Heat 2 tablespoons oil in heavy large pot over medium heat. Add onions and saute until tender and golden, about 8 minutes. Add potatoes; 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, about 3 minutes.
Add sauteed 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 1/3-inch-wide slices. Ladle soup into bowls. Add dollop of sour cream to each bowl. Garnish soup with sliced spinach leaves and serve.
Servings 0