Ok, I'll try. This is going from memory as the cookbook is at home and I'm at work (BTW it's nearly 1pm on a Saturday, I'm in Australia
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Aaaanyway....you put the flour (my recipe calls for 300g from memory) in the food processor, using the sharp blade, with the pinch of salt (this is for savoury of course, I suppose you might be putting sugar in for a sweet shortcrust pasty)...then you add the cold diced butter (I *think* it said 125g, not 100% sure, will have to check at home) and process it until it is blended and resembles fine bread crumbs (takes less than 30 seconds).
Then whilst it is still running, slowly trickle in the 3 - 4 tablespoons of cold water (in Australia 1Tbsp = 20mls). It will come together and form a ball within about 20 seconds, then you tip it out and roll it out on a lightly floured bench/board, and press it into the flan tin as normal.
I then prick the base all over with a fork, blind bake it with rice/baking paper for 15 minutes (moderate oven), then take the rice out and put it back in the oven for 5 minutes to crisp it. The crust is now ready to use.