This is my lighter revision of the classic broccoli-potato soup. The cauliflower gives a slight sweetness and a bit of body to the soup, without the heaviness of potato. This is a very simple, clean-tasting soup, which you can jazz up however you please. The soup will thicken and darken in color a bit as it sits, and it freezes extremely well. —ieatthepeach
medium leeks, white and light green parts only, washed and thickly sliced
Salt to taste
garlic cloves, peeled and lightly crushed with a knife
1 1/2 pounds
cauliflower (about 1 medium head), cored and chopped
broccoli florets (from about 1 medium bunch)
Freshly ground black pepper or white pepper to taste
In a large heavy-bottomed pot, heat oil over medium-low heat. Add leeks, garlic, and a pinch of salt; reduce the heat to low and cook, stirring frequently, for 10-15 minutes, or until the leeks are very soft but not browned.
Add water, increase the heat to medium-high, and bring to a boil. Add cauliflower and a large pinch of salt. Bring the water back to a boil, then reduce the heat to low, cover, and simmer for 15-20 minutes, or until the cauliflower is very tender.
Increase the heat to medium-high, and bring the water back to a rapid boil. Add broccoli florets, cover, and cook for 4-5 minutes, or until the broccoli florets are tender and the cauliflower is falling apart. Turn off the heat and puree with an immersion blender, or in batches in a stand blender. (Let it blend for a while–you want the soup as smooth as possible.)
Season the soup with salt and pepper to taste. Ladle into bowls, and serve warm. Leftovers will keep in an airtight container in the fridge for up to 3 days, or in the freezer for up to 6 months.