Prepare the beets by peeling and chopping them into small cubes.
In a large pot, heat the olive oil over medium heat. Add the chopped onion and sauté for 5-7 minutes until translucent.
Add minced garlic to the pot and sauté for another 2 minutes until fragrant.
Add the cubed beets into the pot and stir to combine with the onion and garlic mixture.
Pour in the vegetable broth and bring the mixture to a boil. Reduce heat and let it simmer for 20-30 minutes until the beets are tender.
Add apple cider vinegar, salt, and pepper to taste, adjusting as needed before blending.
Using an immersion blender or a standard blender, blend the soup until smooth and creamy.
If the soup is too thick, add more vegetable broth or water to reach the desired consistency.
Serve hot, garnished with fresh dill or parsley if desired.