Pre-heat the oven to 200C

Cut pumpkin or squash in half or quarters depending on the size, and scoop out the seeds and fibres inside

Place skin-side up in a roasting dish with a couple of tablespoons of water

Roast for about half an hour, until tender

Keeping the oven on, take the pumpkin out and leave to cool slightly, then peel off the skin, and scoop the flesh into a food processor

Whizz until smooth, then put into a fine sieve or piece of muslin suspended over a bowl and drain for at least an hour

Meanwhile, make your pastry

Sift the flour into a mixing bowl, stir in the salt, then grate in the butter

Rub in using your fingertips until it resembles breadcrumbs, then stir through the sugar

Mix the egg yolk with 2 tablespoons iced water, and sprinkle half over the mixture, then stir together with a knife until it comes together in a paste -- add a little more liquid if necessary

Bring the mixture together with your fingertips, and then roll out on a floured surface to the thickness of a $2 coin

Use it to line a 20cm tart tin

Cover with cling film and chill for 30 minutes

Line the pastry case with greaseproof paper and fill with baking beans

Put in the oven for 15 minutes, then remove the paper and beans, and bake for another 5-10 minutes until the base is pale golden

Remove from the oven

Turn the oven down to 180C

Meanwhile, put 250g pumpkin purée in a large bowl, discarding the excess liquid, and stir in the maple syrup, rum if using, and spices

Taste for sweetness, then mix in the eggs

Gradually stir in the evaporated milk until you have a thick, creamy consistency - you may not need it all

Pour into the pastry case

Bake for about 40 minutes, checking from half an hour onwards, until the filling is set, but still slightly wobbly in the centre

Allow to cool on a wire rack for at least an hour before serving.