In a large pot over moderate heat with the EVOO, add the leek, ginger and garlic. Cook, uncovered for 3 minutes, stirring occasionally. Add the carrots, salt, sugar, and white pepper, stirring to coat with oil. Cover and cook gently until just tender, about 10 minutes. Stir in the broth, and bring to a boil. Reduce the heat to low and simmer, covered, for 15 minutes. Remove from the heat, and allow to cool slightly before pureeing.
Puree the soup in batches in a food processor or blender, or force it through a food mill fitted with the medium blade. (The soup can be prepared up to 2 days in advance, and will taste the better for it. Cool, cover and refrigerate.)
Return the soup to the pan. Add the cream if you are using it, and heat, stirring often, until steaming, about 5 minutes. Adjust the seasoning with lemon juice and pepper sauce, if necessary. Some carrots are sweeter than others, thus the lemon juice to offset the sweetness.
Ladle the soup into bowls, and serve hot, garnished with crispy ginger and/or chopped cilantro, if desired.
For crispy ginger, Peel a 4-inch piece fresh ginger, and thinly shred with a sharp knife. In a small, heavy pot, heat 2 cups canola oil to 375F, and fry the ginger until crispy and golden, about 2 to 3 minutes. With a slotted spoon, remove ginger to drain on paper towels. Use to garnish soup.