Once the pastry is rolled out to the correct size, place the rolling pin in the centre, fold the pastry over and lift it on to the pin.
Then transfer it to a lightly greased, loose-based flan tin, laying it down evenly and carefully.
Now, using your hands, gently press the pastry into the tin to line the base and sides. (If, while you were lifting the pastry, you found it stretched, don't worry – as you line the tin, ease the stretchiness back, especially round the edges). When you've pressed it all round with your fingers, try to ease the pastry that is sticking up above the edges back down, so that what you're in fact doing is reinforcing the edge – if it gets stretched too much it will shrink during cooking. When you've lined the tin, trim off any excess around the edges with a knife, but press the edges again so that you have ¼ inch (5 mm) above the edges of the tin.
Forget about baking beans – it's really all too much bother. Provided you've lined the tin correctly, as above, all you now need to do is prick the base all over with a fork, as this will release any trapped air, which is what causes the centre to rise up. Then brush the base and sides all over with beaten egg, which will provide a sort of waterproof coating so that the pastry stays beautifully crisp even after the filling has gone in. Normally this small amount of beaten egg can be taken from that used for the filling in the recipe.
The oven needs to be pre-heated and, at the same time, you should pre-heat a good solid baking sheet on the centre shelf. The temperature for pastry is usually gas mark 5, 375 F (190 C), but you should always refer to the particular recipe. Then pop the pastry case in to pre-bake for 20-25 minutes or until it is turning golden brown. It's a good idea to have a peep halfway through – if the pastry is bubbling up a bit, just prick it with a fork and press it back down again with your hands.
Once the filled pastry case has been baked, to remove the flan tin, place the tart on a tin or jar, loosen the pastry all round with a small knife or skewer and ease it down.