Stroganina from fish

I have lived in Western Siberia for 16 years and, naturally, I know the culinary recipes of many dishes of the national cuisine of the peoples of the north. For example, one of my favorite snacks is fish stroganina. Now I will share with you the way of cooking this food. So, first we take a fresh fish, clean it, gut it, take out the bones, leaving only the fillet. Now we take a deep dish, pour half a cup of apple cider vinegar into it, add a peeled onion, cut into rings or half rings (you can also chop it finely or grind it in a blender, grate it), salt and pepper to your personal taste. Now we take the burning red pepper and also add it to the total mass, mix everything thoroughly. Then we put the fish in the prepared marinade and leave it under the yoke for a day in the holoidlnik to soak. After this time, we take out the fish, dry it and put it in the freezer. If necessary, we take it out, cut it into thin plates and serve it to the table as a snack.