Ingredients:
1 large leek
1 tablespoon unsalted butter or olive oil
½ head cauliflower, cored and divided into large flowerets
2 ½ cups water, vegetable broth, or chicken broth
1 cup plain yogurt or sour cream
Salt and pepper
Directions:
Half the leeks lengthwise, then slice them into half-moon shapes approximately ½-inch thick (use white and light green parts only). In a colander, rinse the leeks thoroughly to remove any dirt between layers.
In a large pot, melt butter over medium-high heat. Add the leeks and cook, stirring frequently, until they’re tender. Do not let the leeks brown.
Add the cauliflower and water or broth and bring to a boil. Reduce heat to a simmer, cook until the cauliflower is falling-apart tender. Add the yogurt and return the soup to a boil. Remove from heat.
Using a blender or food processor, purée the soup as finely as possible. Season with salt and pepper. If needed, thin to desired consistency with milk or water. Serves 4 to 6

