Stew chopped onions and carrots in a pan, add liver, salt and pepper. Remove from heat, add butter and beat with blender until smooth. Mix eggs, salt, pepper, soda and milk in separate bowl, pour out on a baking tray and bake for 20 min at 180 С°. For the sauce chop the egg, processed cheese, garlic finely, add mayonnaise and mix well. Put sauce and liver on the baked eggs, add boiled and sliced carrot in one corner and make the roll. Put in fridge for 2 hours.