First, let’s prepare the filling. Cut 2 onions into small cubes.
Fry the onion in three tablespoons of vegetable oil until transparent.
Put fried onions, 200 grams of pre-cooked rice, and 160 grams of tuna in a bowl. Add 0.5 teaspoon of ground black pepper. Mix everything well. The filling is ready.
Put 5 eggs, 200 milliliters of sour cream, 200 milliliters of mayonnaise, 1 teaspoon of baking soda, and 5 tablespoons of flour in a mixer bowl. Stir in a mixer until a homogeneous dough is obtained.
Line the form with baking paper. Pour a third of the prepared dough into the mold. Distribute the fish and rice filling on top with an even layer.
Fill with the remaining dough. We bake in a preheated oven at a temperature of 150 degrees Celsius for 1 hour.
Put the finished rice casserole with tuna on a wooden board, let it cool slightly. Peel the fish casserole from the paper put on a dish and serve with fresh vegetables and sauce.