- 3 tablespoons butter
- 2 large russet potatoes, peeled, cut into 1/2-inch pieces
- 1 1/2 medium onions, chopped
- 3 tablespoons all purpose flour
- 2 3/4 cups (or more) canned vegetable broth
- 1 3/4 cups milk (do not use low-fat or nonfat)
- 2 1/4 cups chopped trimmed watercress
- Melt butter in heavy large saucepan over medium heat. Add potatoes and onions. Stir until coated with butter, about 1 minute. Sprinkle flour over; stir 1 minute. Add 2 3/4 cups broth and milk. Cover pan. Boil gently until potatoes and onions are tender, about 10 minutes.
- Puree soup in batches in blender. Return to pan. Add 1 3/4 cups watercress. Bring back to simmer. Season with salt and pepper. Thin with more broth, if desired.
- Lade soup into bowls. Garnish with remaining 1/2 cup watercress.