Place a deep frying pan over medium heat. Melt butter in the pan. Add chopped carrots and onions. Fry, stirring, for 3-4 minutes.
Transfer to a clean bowl. Add chopped mince, salt, ground black pepper, fish spices and 1 raw egg to the vegetables. Mix well.
Spread out some foil and place the minced fish on it in a rectangular layer.
Place boiled eggs one after another on one edge of the rectangle, like a chain. Roll up tightly.
Wrap the roll in foil. Place in the oven for 30 minutes.