With apologies to those of you who could work it out for yourselves, this is my response to the demand on Facebook to publish the recipe. I am a member of the campaign for real recipes so will use metric and imperial depending on which is handiest. I will also tell it like it is.
The basic soup recipe is John Tovey's from the 1970s and is perfect. You need one onion per portion and 1oz of butter per onion. Sweat them and soften them until they're soft and sweaty. Add a glug of sherry per portion (so a quarter of a pint if you're serving about 6).
Meanwhile peel a medium butternut squash having first cut a one inch piece off the top to make tonight's pasta dish with roast butternut squash. De-seed and set a few seeds aside for later garnish.
Now I take the peelings, the seeds, a few bendy carrots, the odd firm outer cabbage leaf and basically anything else in the house that has moved on from eat-by to rot-by and stick it in a big pot with a couple of whole garlic cloves and a bay leaf and bingo, that will be my stock where bingo equals about three hours later. So you should have started this two hours before the soup but don't worry, you can get a usable stock in an hour and if necessary can use a veggie stock cube in its place or additionally. You will need about a litre of stock for three or four portions of soup.
Chop the squash meat into small bits (about a centimetre square) and add it to the onion and sherry mix. Add a two centimetre lump of fresh ginger, peeled and chopped finely, plus salt and black pepper.
Now, and this is important so stop speed-reading, put a double thickness of dampened greaseproof paper over the soup and cover with a lid. This allows steam to get out but keeps most of the liquid in the pan. Simmer on lowest setting possible for an hour. If you burn yourself on escaping steam when you check it hasn't gone dry, it hasn't gone dry. So don't check. Add some water to the pan now the steam has escaped and run your burn under cold running water for ten minutes.
Allow to cool then liquidize, adding the stock slowly as you go. You may have to do it in two batches to avoid flooding the work surface with soup when taking the liquidizer jug off. (Do you detect more bitter experience here readers?) Return soup to the pan and warm through when needed. Check seasoning.
Serve with crusty bread and butter. Garnish with a swirl of cream and some roasted pumpkin seeds.