Place cubed potatoes and carrots in a large 5-quart pot. Then, fill the pot with clean water, leaving just about 1 inch of space at the top. Add peppercorns and bay leaves and bring to a boil on high heat.
Meanwhile, heat up a large frying pan with olive oil on medium high heat. Add onions and saute for about 3-4 minutes. Add carrots and bell pepper and saute for another 3-4 minutes. After that, add beets, tomatoes and ketchup. Cook for 5 more minutes and then turn off the heat.
At this point, our soup should be boiling and the vegetables should be cooked half-way through. I would recommend removing the peppercorns and bay leaves with a slotted spoon.
Add cabbage and the beet mixture into the boiling soup. Reduce the heat to low, add salt and sugar, and cover the pot with lid and cook for 15 more minutes.