1 leek, whites and light green parts only, thickly sliced
1-1/4 teaspoons kosher or sea salt, divided (use less if broth is salty)
Freshly cracked, finely ground black pepper
¼ cup all-purpose flour (or potato starch on Passover)
1 large or 2 small cauliflowers (about 2 pounds), leaves removed and cut into florets
3-1/2 to 4 cups low sodium chicken broth (or parve or vegan chicken stock)
Optional toppings include croutons, tiny steamed cauliflower florets, or sliced chives.
Instructions:
Heat olive oil in a soup pot or Dutch oven. Add onions, leeks, ¼ teaspoon salt, and a couple grinds of pepper. Sauté on medium low heat until soft, about 10 minutes. Add flour and stir for a minute.
Add the cauliflower, the rest of the salt, several grinds of pepper, and put in enough broth to almost cover the cauliflower. Cover the pot with the lid ajar. Turn the flame up to bring the broth to a boil, then reduce the flame so that the soup simmers for 20 minutes.
Let the soup cool slightly. Purée the soup in batches in a high-powered blender until smooth and creamy. Take care with warm soup in a blender. Taste and add salt and pepper if needed. Check consistency and add a little more broth if you prefer a thinner consistency.
Serve warm. Use one or more optional toppings if desired. In addition, the soup can be made ahead and re-heated.
Recipe by Danas Table at https://danastable.com/cauliflower-soup-2/