Preheat the oven to 160’C
Cook the squash and potato in pan a pan of boiling water for 7-8 minutes
Heat a large saucepan to a medium temperature and cook the onion until soft.
Add the bacon and cook until coloured and a little crispy and then add the broccoli and cook for a further 5 minutes until softened.
Add the carrot, peas and spinach and cook off until all the excess moisture has disappeared from the pan.
Grease either 1 medium oven dish or 2 small dishes with a little butter.
Make one layer of potato and squash to cover the bottom of the tin and then top with half the bacon mixture.
Top with another layer of the potato mixture and then the remaining bacon mixture.
Place one final layer of potato and squash and then sprinkle over the goats cheese.
Whisk together the yoghurt, milk, eggs, mustard and salt and pepper until smooth and the pour slowly over the gratin (you might not need it all but give it a chance to soak into the gratin).
Bake in the oven for 40 minutes and serve with some seasonal greens.