Heat oil in a large pot over medium heat. Add beets, carrots, onion, ginger, sage, garlic, lemon zest, salt, and pepper.
Cook for 10-15 minutes, stirring occasionally, until vegetables are soft and fragrant.
Pour in vegetable broth and bring mixture to a boil.
Reduce heat and simmer for 40-50 minutes until beets are completely tender.
Using an immersion blender or regular blender, blend soup until completely smooth.
Taste and adjust seasoning with lemon juice, salt, and pepper as needed.
Serve warm with desired garnishes.