1. Heat a large skillet over medium heat. Add 2 tablespoons oil; swirl to coat. Sprinkle sugar over oil; cook 1 minute or until sugar melts. Add thinly sliced shallots, stirring to coat. Cook 15 minutes or until golden brown, stirring frequently. Set caramelized shallots aside.
2. Crush 3 garlic cloves. Cut 2 lemongrass stalks in half lengthwise. Combine crushed garlic, halved lemongrass stalks, 4 cups water, 1 teaspoon turmeric, anchovy paste, and 2 ginger slices in a large Dutch oven. Add fish; bring to boil over high heat. Cover, reduce heat, and simmer 10 minutes or until fish flakes when tested with a fork. Remove fish from pan. Strain broth through a sieve into a large bowl, reserving 4 cups stock, discarding solids.
3. Coarsely chop white portion of remaining 2 lemongrass stalks; reserve green portion for another use. Place chopped lemongrass, remaining 3 garlic cloves, remaining 2 ginger slices, crushed red pepper, and 7 shallots in a food processor; process until a coarse paste forms.
4. Place garbanzo bean flour in skillet; cook over medium heat 2 minutes or until fragrant and slightly darker in color, stirring constantly with a whisk. Pour flour into a small bowl; set aside.
5. Add 1 tablespoon oil to Dutch oven; swirl to coat. Add shallot paste, and cook 2 minutes or until fragrant, stirring occasionally. Return fish to pan; cook 3 minutes, stirring gently to coat with paste. Remove fish mixture from pan; set aside.
6. Add remaining 1/2 teaspoon turmeric, reserved fish stock, fish sauce, and paprika to pan; bring to a boil. Gradually add remaining 3/4 cup water to garbanzo bean flour, stirring with a whisk until smooth. Gradually add flour mixture to boiling stock mixture, stirring constantly with a whisk. Return to a boil. Reduce heat, and simmer 12 minutes or until slightly thick, stirring occasionally. Add remaining 3 halved shallots; simmer 10 minutes or until shallots are tender. Add fish mixture; simmer just until hot.
7. Cook noodles in boiling water 2 minutes or until tender; drain. Spoon 1/2 cup noodles into each of 6 bowls. Ladle 1 1/3 cups soup into each bowl, ensuring each serving gets a shallot half. Top each serving with 2 tablespoons caramelized shallots, 1 tablespoon cilantro, and about 1 tablespoon green onions. Serve with lime wedges.