Peel the onion and cut into half rings. Peel and grate the carrots. Break the eggs into a bowl, add salt and black pepper and mix well. Pour flour into a plate. Grate the cheese.
Remove the film from the liver. Cut the liver into pieces about 1 centimeter thick.
Roll the liver pieces in flour, then dip them in beaten eggs and place in a frying pan in heated vegetable oil (2 tablespoons).
Fry for 1 minute on each side, no need to cook until done.
Next, place the pieces on a baking sheet greased with vegetable oil.
Fry the chopped onion in vegetable oil (2 tablespoons) until transparent, then add the carrots and cook for 3 minutes, stirring constantly.
Remove from heat, transfer to a bowl and add 2 tablespoons of sour cream. Add salt to taste and mix well. Place the filling on the liver pieces and sprinkle grated cheese on top. Place in an oven preheated to 180 degrees for 10 minutes.
When serving, sprinkle the liver pieces with fresh herbs.