Finely chop the vegetables and mix them with the remaining ingredients for the filling. Leave to macerate for 48 hours.
To prepare the pastry mix the flour, eggs, salt and water. Add the melted butter a mix into a dough. Leave to rest for 1 hour.
Preheat oven to 160°C.
Roll out the pastry. Pile the filling on the pastry by forming a clump. Fold the pastry over the filling and press to close the edges. Make 2 or 3 chimneys (decorate their rims with pastry). Trace a criss-cross pattern with a fork.
Brush with the egg yolk mixed with a little cold water. Put in the oven at medium heat for some 2 hours (until the cooking juices comes out clear). Leave to cool completely.
To make the aspic cook the pig's trotters and ears with the mirepoix and salt in a stock pot, cover with water for some 3-4 hours.
When cool strain and stir through the riesling. Pour this aspic through the chimneys into the pastry. Leave to cool in the refrigerator for 3-4 hours to allow the aspic to set.