Heat a little oil in a large pot and add the lemongrass. Let it sizzle for about 1 minute until fragrant. Add the carrots and golden beets. Cook the vegetables in the oil for 2–3 minutes before turning and cooking 2–3 minutes more. Season with salt and pepper.
Bloom the curry powder:
Add the curry powder to the pot and cook, stirring to coat the vegetables with the powder, until fragrant, about 1 minute.
Simmer the soup:
Pour in the water or stock and bring to a boil. Simmer for 30–40 minutes until the carrots and beets are fork-tender. Taste and season with salt and pepper.
Blend the soup:
Add the coconut milk and blend the soup with an immersion blender until smooth and creamy. Taste and season once more.
To serve:
Ladle the soup into bowls. Serve with cooked white rice or toasted naan. Garnish with fresh cilantro and lime wedges, if you like. Enjoy!