Wash the snails and put them to boil for 30-40 minutes. Remove the meat from the shells but keep the shells. Fry the chopped onions and garlic in heated butter, and once they soften, add the chopped parsley and dill. Salt to taste, add the nutmeg and white pepper.
Add the chopped snails, stir for a minute and transfer the mixture into a food chopper. You can also use a hand blender. Add the strained yoghurt and cream to the snails and blend.
If the mixture turns out runny, thicken it with a little starch. Fill it in the shells and serve as an appetizer.