Mix the flour and salt in a bowl. Add the butter and rub together using your hands to form an even, crumbly mixture. Pour in the water and mix quickly to form a soft dough; do not knead. Flatten the dough, cover and chill for approx. 30 mins.
In a large bowl, mix the potatoes and all the other ingredients up to and including the pepper.
Roll the dough into a circle approx. 4 mm thick on a sheet of baking paper, scatter the bread on top, add the topping, pears and nuts, leaving a border of approx. 4 cm all the way around. Fold in the edges, press down gently, glaze the edges with a little egg. Mix the remainder of the eggs with the milk and pour this sauce on top of the topping in the middle.
Approx. 55 mins. in the lower half of an oven preheated to 180°C.