Butternut Squash, Mustard & Gruyère Gratin
- Heat the butter and oil in a lage frying pan, add the onions and cook slowly over a low-medium heat, stirring occasionally, for about 10-15 minutes until golden and soft.
- Meanwhile put the garlic and half the sage in a saucepan, add the cream and milk and heat gently, not allowing the mixture to boil, for about 5 minutes. Remove from the heat and leave to cool for 10 minutes. Remove the sage and garlic. Stir in the mustard and season well.
- Heat the oven to 180C/160 FAN/GAS 4. Layer the pumpkin slices, fried onions, most of the cheese and most of the infused cream into a large baking dish finishing with a layer of cream. Once you used up all the ingredients scatter over the remaining cheese and sage leaves. Cover and bake for 45 minutes.
- Uncover the dish and increase the heat to 200C/180 FAN/GAS 6. Cook for a further 20/30 minutes until golden brown and tender all the way through. Leave to cool for about 10 minutes before serving, the dish will be extremely hot and you don't want to burn your mouth.