Crumble the sausage into a skillet over medium-high heat. Cook and stir until no longer pink. Remove from heat and set aside.
Fill a large pot halfway with broth and bring to a boil. If using sausage add to broth, and bring back to a boil. Add the beets and cook until they have lost their color. Add the carrots, potatoes and garlic, simmer until tender (about 15 min). Add the cabbage and the can of diced tomatoes.
Heat the oil in a skillet over medium heat. Add the onion, and cook until tender. Stir in the tomato paste and water until well blended. Transfer to the pot. Simmer another 5-10 minutes, and adjust seasoning (salt, pepper and sugar) to your liking. Cover, turn off heat and let soup stand for about five minutes.
Ladle into serving bowls, and garnish with sour cream and fresh parsley.