How to make
Finely chop the onion and fry it in the oil, until it softens.
Add finely chopped parsley, walnuts, black pepper and salt. Mix well.
Clean and wash the carp. Leave it in a pot of cold water for 2 hours, in which you have also added the sliced lemon.
Fill the carp with the resulting vegetable mixture and sew it up. Spread it with oil and bake at 360°F (180°C) for an hour and a half.