This soup’s secret ingredient—an apple—lends a touch of tangy sweetness that complements the curry’s spice. Letting the soup cool 20 minutes before blending helps deepen the flavors.
1. Heat oil in large pot over medium-high heat. Add onion, and sauté 5 to 7 minutes, or until soft and golden. Stir in apple, curry powder, and garlic, and cook 2 minutes more, or until curry powder turns deep yellow.
2. Add cauliflower and vegetable broth, and bring to a simmer. Cover, reduce heat to medium-low, and simmer 20 minutes. Cool 20 minutes, then blend in food processor or blender until smooth. Stir in honey and vinegar, and season with salt, if desired.