* If the prescribed walnut ketchup is not available, replace it with vinegar in which walnuts were preserved, or wine vinegar *.
Place the oysters in a saucepan and add crumbled onion, parsley, white bread, walnut ketchup, butter, Stangenzeller, juice of a lemon and salt, pepper, zest and a little cayenne pepper.
Cook over low heat, stirring throughout. Now pour in the beaten eggs and stir in thoroughly.
Fill the cleaned oyster shells with this mixture.
Cover with the fried breadcrumbs and bake in the heated stove at 220 °C (gas stove level 4-5) for 10 min.
Garnish with the lemon slices and bring to the table.