Remove the top from the squash and scoop out the insides, reserve the flesh. 

Peel and thinly slice the potatoes.

Slice the squash the same 3mm thickness as the potatoes.

To build the gratin simply layer the sliced squash, potatoes and add 50ml cream, a grated of cheese and season well, repeat this until the pumpkin is completely full.

Place the gratin on a tray and bake at 180c with the lid on for 30 minutes and remove the lid for the final 15-20 minutes.

To check that the gratin is cooked place a cake tester or small knife inside, you are looking for little or no resistance.

The gratin is ready to serve.