Cook the sausages, peel them and leave them to cool down.
Make a béchamel sauce with the milk, butter and flour and add the creamy mushroom and truffle paste.
Roll out the puff pastry, cover it with cured ham and spread on the béchamel sauce (the length of the sausage and the same width as well, making a square). Put the sausage on top and wrap it with the pastry. Brush it with egg yolk and decorate as you like. Bake at 200 C for about 10 minutes.
Cook the potatoes, peel them and mash them, then add the creamed pumpkin and the parmesan, seasoning with salt and pepper.
Cut the sausages into slices and plate up by garnishing it with the pumpkin mash and the balsamic vinegar pearls.