Combine the shredded beets, carrots, onion, water, and salt in a large saucepan or soup pot. Bring the mixture to a boil over medium-high heat, then reduce the heat to low. Cover and let it simmer gently for about 20 minutes, allowing the vegetables to soften and release their natural sweetness.
Pour in the beef broth and stir in the shredded cabbage along with the butter. Continue cooking uncovered for another 15 minutes, stirring occasionally, until the cabbage is tender and the broth turns a deep, rich red.
Just before serving, stir in the lemon juice to brighten the flavors and add a subtle tang that balances the soup’s natural earthiness.
Ladle the hot borscht into bowls and, if desired, top each serving with a dollop of sour cream and a sprinkle of chopped chives or fresh dill. Serve warm for a comforting meal or chilled for a refreshing twist on this classic Eastern European soup.