I love, love, love cauliflower in all shapes and forms, and this soup is SO creamy and delicious! It was originally a recipe from the Green Bean Delivery Company, but I have made several changes and made it my own. Enjoy!
Halve the leeks lengthwise, then slice them into half-moon shapes about 1/2 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 are tender--do not let them brown.
Add the cauliflower, broth, and half and half and bring to a boil. Reduce heat to a simmer, cook until the cauliflower is fall-apart tender, about 25 minutes. Add the sour cream, salt, pepper, and garlic powder and return the soup to a boil. Remove from heat.
If you prefer a thinner soup, use a blender or food processor and puree the soup as finely or coarsely as you like it. If needed, thin to desired consistency with milk or water.
If you prefer a chunkier soup, as I do, simply chop the tender cauliflower florets gently with a wooden spoon while in the pot.
Add the cheese to the soup while it is hot, and stir until cheese is melted.