Heat the olive oil in a large pot over medium heat. When the oil is shimmering, add the chopped onion. Sauté for about 5-7 minutes, or until the onions are clear and soft. If necessary, add a tablespoon or two of water to prevent sticking.

Next, add the chopped garlic, minced ginger, red Thai curry paste, and tamari or soy sauce. Sauté for 2 minutes, or until the garlic is fragrant.

Now, add the broth, coconut milk, chopped carrots, lemongrass stalks, and crushed red pepper flakes to the pot. Bring the mixture to a boil, then reduce to a simmer. Cover and let it simmer for 20 minutes.

After simmering, remove the lemongrass stalks from the pot. Carefully transfer the soup to a blender in batches and blend until smooth. Alternatively, you can use an immersion blender to blend the soup right in the pot.

Return the blended soup to the pot, stir in the lime juice, and adjust seasonings to your taste. If the soup is too thick, you can stir in some extra broth to achieve your desired consistency.

Serve the soup with chopped basil, finely chopped peppers, sprouts or microgreens, sliced avocado, or a swirl of coconut milk or cashew cream, if desired!