First of all, make the pastry.
Remove a pack of butter from the fridge, weigh out 4oz (110 g) then wrap it in a piece of foil and return it to the freezer or freezing compartment of the fridge for 30-45 minutes. Then, when you are ready to make the pastry, sift the flour and pinch of salt into a large, roomy bowl. Take the butter out of the freezer, fold back the foil and hold it in the foil, which will protect it from your warm hands. Then, using the coarse side of a greater placed in the bowl over the flour, grate the butter, dipping the edge of the butter into the flour several ties to make it easier to grate. What you will end up with is a large pile of grated butter sitting in the middle of the flour.
Now take the palette knife and start to distribute the gratings into the flour - don't use your hands yet, just keep trying to coat all the pieces of fat with flour. Then sprinkle 2 tablespoons of cold water all over, continue to use the palette knife to bring the whole thing together, and finsih off, using your hands. If you need more moisture, that's fine - just remember that the dough should come together in such a way that it leaves the bowl fairly clean, with no bits of loose butter or flour anywhere. Now pop it into a polythene bag and chill for 30 minutes in the fridge.
Meanwhile, find a lidded saucepan that will fit the pears comfortably, laying them in the pan on their sides. Now mix the wine with the sugar and pour this over the pears, then add the cinnamon stick and vanilla pod. Put the lid on the pan and gently simmer the pears for 45 minutes, until tender when tested with a skewer. Turn them over halfway through the cooking time so the other half sits in the wine and they colour evenly. Towards the end of the cooking time, pre-heat the oven to gas mark 7, 425°F (220°C).
Then roll the pastry out on a lightly floured surface to 1/8 inch (3 mm) thick and cut it into six 4 inch (10 cm) circles, then arrange them on the baking sheets. Now lift the pears from the liquid and halve them by first making a slit in the stalk as you press it on to a flat surface. Then stand each pear upright and cut through the split stalk, halve the pears and remove the cores. Now you need to slice each half into a fan, so take a sharp knife and, starting from the top of the stalk end, about ½ inch (1 cm) in, slice the pear downwards and at a slight angle so you end up with the slices of pear fanning out but still attached to the stalk. Now place each half pear on to a pastry base and fan it out, then place the baking sheets in the oven for 10-12 minutes, one on the top shelf, the other on the next one down, swapping them over halfway through the cooking time.
Meanwhile, you need to reduce the poaching liquid, so first remove the cinnamon stick and vanilla pod, then place the saucepan over a high heat and let it bubble for about 5 minutes. Then, in a cup, mix the arrowroot with a little cold water until you have a smooth paste, then add this to the saucepan, whisking with a balloon whisk all the time. This will thicken the sauce slightly, then remove it from the heat and leave it to cool. When the tarts are ready, remove them from the oven.
Serve hot or cold but, just before serving, pour a little of the syrup over each tart to give them a pretty glaze.
You can also watch how to make Delia's Flaky Pastry in our Cookery School Video on the right