Bring 1.5 liters of cold water to a boil in an enamel pot over medium-high heat. Add beet strips and 1 tablespoon vinegar.
Return to a boil, cover with a lid, reduce heat to low, and simmer for 40 minutes.
Remove from heat and let cool to room temperature.
Strain the broth through a sieve into a clean jar or enamel pan, reserving the cooked beets. Place the broth in a warm location for 8-10 hours to develop sour flavor.
Peel 100-150g carrots, cut into large pieces, and boil in a separate pot over medium heat until tender, about 15 minutes.
Drain the carrots and cut into small cubes or strips.
Peel and cut 3-4 cucumbers into strips. Finely chop 1 bunch of green onions.
Dice the reserved cooked beets. In a large bowl or pot, combine diced beets, diced carrots, sliced cucumbers, and chopped green onions. Add 1.5-2 teaspoons salt, 2 tablespoons vinegar, and 1 tablespoon sugar.
Remove the soured broth from the warm location and refrigerate until chilled to 8-10°C (46-50°F).
Pour the chilled beet broth over the vegetables and stir to combine.
Boil 2 eggs in a separate pot over medium heat for 10 minutes. Peel and cut into small pieces.
Finely chop 0.5 bunch of dill or parsley.
To serve, place cold borsch in a bowl, top with chopped egg, add roughly 1 tablespoon sour cream, and sprinkle with fresh herbs.