This soup is deceptive: it's smooth and creamy, but contains no dairy products. Instead, a potato added to the base gives the soup silkiness. Its hearty flavor will also deceive, since it takes only 5 minutes instead of the usual 25.
MAKES 6 SERVINGS
Peel the potato and cut it into 1-inch (2.5-cm) pieces. Remove any leaves from the cauliflower and cut out the core; chop the remaining cauliflower into 1-inch (2.5-cm) pieces.
In the pressure cooker pot, saute the onion in the butter until softened, about 2 minutes. Add the broth, potato, cauliflower, and ½ teaspoon salt. If using an electric pressure cooker, switch off the saute function.
Lock the lid into place and cook on high pressure for 5 minutes. Quick-release the steam. When the pressure valve drops, remove the lid, tilting it away from your face to allow residual steam to escape.
Stir the curry powder into the soup. Let the soup stand until no longer steaming hot, then puree it in batches in a blender (or with an immersion blender directly in the pot) until very smooth. Return the pureed soup to the pot and season to taste with salt; reheat if necessary. Ladle into bowls, top with the croutons, and serve right away.