Heat beef stock in a large pot.
Add one whole potato to the pot. Meanwhile, cut another 4 potatoes, first slice them lengthwise into slabs. Then slice them into thick fry-like shapes. Finally, cut potatoes into large cubes. Add potatoes to the pot. Cook until soft. Then mash the whole potato and bring it back to the pan.
In a pan, heat 2 tbsp of cooking oil over medium heat. Add the chopped onion and sauté until it becomes translucent. Add julienned carrots to the pot. Sauté for about 5-7 minutes until the carrots start to soften.
In a saucepan heat 1 tbsp of cooking oil. Sauté the beetroot for about 5 minutes. Stir in the tomato paste and continue to cook for another 5 minutes, allowing the flavours to meld. Add vinegar and sugar if using.
Once the potato is ready, add sauteed vegetables in the pot. Simmer for around 5 minutes. Then add shredded cabbage and simmer for about 3-5 minutes (depends of the cabbage softness)
Season the Borscht with salt, pepper to your taste. Add a couple of bay leaves to the pot for flavour. Add minced garlic.
Serve it hot, optionally with a dollop of sour cream on top and chopped dill. Enjoy your delicious homemade borscht!