In a large pot or Dutch oven, heat the olive oil over medium heat. Add the onion, garlic, and carrot and cook until the vegetables are tender, about 5-7 minutes.
Add the chicken broth, water, fish sauce, brown sugar, turmeric, cumin, coriander, and chili flakes (if using) to the pot. Bring the mixture to a boil.
Add the rice noodles and cook until they are soft, about 5-7 minutes.
Stir in the sliced chicken or tofu and bean sprouts and simmer for an additional 2-3 minutes.
Garnish the soup with cilantro, basil, and lime wedges. Serve hot and enjoy!