1. Steam the potatoes at the heart temperature of 90°C.
2. Scrub the baking potatoes, leave them to cool and slice them about 0.5 cm thick.
3. Sauté the potatoes with olive oil in a frying pan.
4. Brown sausages in a pan.
5. Tip into a bowl the ricotta cheese, eggs, grated cheese and pumpkin cream. Purée until smooth. 
6. Roll out the pastry until large enough to line a 28cm tart tin.
7. Pour the filling in the pastry case, lay down potato slices and scatter the browned sausages over the surface.
8. Bake at 165 °C in a convection oven for 45 minutes.