Cut the onion and the carrot into small cubes.
Heat the tablespoon of vegetable oil into a soup pot.
Fry the onion and the carrot for a few minutes, until soft.
Cover with water (around 3-4 litres).
Add the green beans to the pot, cut in thirds.
Add salt to taste and bring to boil.
Add the chopped courgette and simmer for 15-20 minutes, until the green beans are soft.
In a separate small pot heat the bors until it starts to boil.
Turn the heat off and pour it over the soup.
Meanwhile, mix the sour cream with the grated garlic.
When the green beans are soft, turn the heat off and start dressing the soup.
Add one ladle of hot soup to the bowl with sour cream and garlic, and whisk fast.
Continue to do so until the sour cream has reached the same temperature as the soup.
Then, pour the sour cream into the soup and mix to incorporate everything.
Serve the soup hot, with crusty bread.