Servings: Serves 6
Heat the oil in a large saucepan over high heat until hot. Reduce the heat to medium, add the chorizo and cook, stirring occasionally, until the pieces are lightly browned on both sides, about 5 minutes. Transfer the chorizo with a slotted spoon to a plate. Add the onion to the pan and cook, stirring occasionally, until softened, about 5 minutes.
Meanwhile, cut 2 cups of small florets from the cauliflower and chop the rest. Peel and thinly slice the potato. When the onion has softened, add the chicken broth, chopped cauliflower and the potato to the saucepan; bring the mixture to a boil over high heat. Reduce the heat to low and simmer for about 5 minutes or until the cauliflower and potato are very tender. Transfer to a blender in 3 or 4 small batches and puree until very smooth.
Measure the pureed soup and return it to the saucepan. Add water, if necessary, to make 7 cups. Stir in the reserved cauliflower florets and simmer for 4 minutes or until they are almost tender. If you are using mustard greens or kale, add them to the soup with the florets. When the florets are just tender, stir in the chorizo and the lemon juice; add salt and pepper to taste. If using spinach, stir it in with the chorizo. Ladle the soup into bowls; sprinkle each with some paprika and serve with garlic bread, if desired.