Heat the oil in a large ovenproof pan over a low heat and slowly fry the onions, carrots and celery for 10-15 mins until soft but not golden. Meanwhile, peel the squash and cut the neck from the bulb. Halve the bulb, remove the seeds and chop into 3cm pieces. Finely slice the squash neck on a mandoline or with a sharp knife into 2mm-thick slices. Stack these in order as you slice.

Heat the oven to 200C/180C fan/gas 6. When the onions are tender, stir in the garlic and herbs. Fry for 1 min, then add the parsnips and chopped squash. Cook for another 5-8 mins until the veg has just softened, then sprinkle in the flour. Stir well, then mix in the wine. Bubble for a few minutes, then add the stock and beans. Bring to a simmer, then stir in the mustard and crème fraîche. Simmer uncovered for a few minutes until the sauce thickens – it needs to be quite thick or the squash will sink. Remove from the heat, fold in the chopped sage, lots of black pepper and a little salt.

Starting from the outside edge, arrange the squash slices over the stew from largest to smallest in a tight spiral, working into the middle. Top with the sage leaves, drizzle with a little oil and bake for 35-40 mins until the squash is tender, the filling bubbling and the veg soft. Serve with spinach and roasties.