Before You Start
Preheat the oven to 400°F. Using your fingers, lightly grease a rimmed baking sheet with a little oil, then lightly grease the garlic and shallot and place on the baking sheet.
Whisk together the yogurt, lime zest and juice, chili powder, cumin, salt, pepper, garlic powder, and curry powder in a large bowl. Add the cauliflower and toss to coat with the yogurt mixture. Transfer the cauliflower to the baking sheet with the garlic and shallot. Roast until the cauliflower is lightly browned, 30 to 40 minutes. Set aside to cool. When cool enough to handle, squeeze the garlic out from their skins.
Place the chicken broth in the blender, followed by the garlic, shallot, and cauliflower. Select the SOUP setting. Once the cycle finishes, slowly add the cream to the emulsion cup so it blends in while the blender is running (1 cup of cream won’t fit in the emulsion cup all at once so it needs to be added gradually). Select MANUAL/LO, gradually increasing the speed to SPEED 8 and blend, 30 to 40 seconds. Season with salt and pepper. Divide the soup among bowls and serve.
Variation: Cauliflower Coconut Soup
Substitute coconut milk for the heavy cream. For a vegetarian version, substitute low-sodium vegetable broth for the chicken broth.
For this cauliflower soup, try adding a sprinkle of curry powder stirred into plain yogurt, a few fresh cilantro leaves, or a couple of roasted cauliflower florets that you hold back from the blender.