
Pour the infused milk through a sieve into a jug (discard the flavourings), then gradually stir into the butter/flour mixture (known as a roux), stirring constantly until smooth.
Melt the 35g butter in a medium saucepan, then stir in the flour and cook over the heat for 3-4 minutes. Turn the oven down to 190☌/170☌ fan/gas 5. Once the squash is tender, take out of the oven and transfer to the prepared soufflé dish, then set aside. Tip the dish on its side and roll around until coated with crumbs. Brush the inside of the soufflé/baking dish liberally with melted butter, then scatter in the breadcrumbs. Bring the mixture almost to the boil, then remove from the heat and set aside to infuse.
Put the milk, shallots, peppercorns and bay leaves in a pan.Put the squash on a roasting tray, toss with the olive oil, season with salt and pepper, then roast for 30-35 minutes until soft and golden.