Heat oil in a large saucepan over medium heat. Sauté onion until golden brown. Add ginger and garlic and cook for 2 minutes, stirring frequently.

Add beets, carrots, and stock. Reduce heat to low and simmer covered until beets and carrots are tender, about 25 minutes.

In a food processor, purée soup in batches. Taste soup and adjust seasonings.

Serve hot or cold, garnished with cilantro leaves.