Peel the potatoes and carrots and cut into small pieces. Also cut the peppers into small pieces. Heat the oil in a pan and fry the minced meat until crumbly. Deglaze with the canned tomatoes, tomato paste and stock. Add the potatoes, carrots and the peppers. Cover everything and let simmer for about 40 minutes over medium heat. To reduce it, let it simmer for about 10 minutes without the lid. At the end, season with the spices and stir in the sour cream.