Heat 2 tablespoons vegetable oil in a large pot over medium heat. Add the carrots, onion and ginger and cook until the vegetables are just soft, about 5 minutes. Season with salt and pepper. Add the star anise, carrot juice and 3 cups water, then cover and boil until the vegetables are tender, about 20 minutes.
Meanwhile, cut the tofu into 1-inch cubes. Mix the cornstarch and curry powder on a shallow plate and season with salt. Pat the tofu dry and roll it in the cornstarch mixture. Heat the remaining 6 tablespoons oil in a large skillet over high heat. Add the tofu and fry, turning, until golden and crisp on all sides, about 5 minutes. Drain on paper towels and season with salt.
Discard the star anise. Transfer the soup to a blender and puree in batches, or puree directly in the pot with an immersion blender. Thin with water, if needed, and season with salt and pepper. Ladle into bowls and top with the fried tofu. Garnish with cilantro, if desired.