This is from the Delia Smith’s Complete Cookery Course (1982), page 565.
340g plain flour (harina de trigo)
255g margarine (if you can’t find “block margarine” in Spain, just use butter instead) – [margarina dura, en bloque o, en su defecto, mantequilla]
Pinch salt (pizca sal)
Cold water (agua fría)
The margarine has to be “block” (not soft ‘tub’ margarine, which is not suitable). Take it hard from the fridge, weigh out the required amount, then wrap it in a piece of foil and return it to the freezing compartment of the refrigerator for half an hour. Meanwhile sift the flour and salt into a mixing bowl.
When you take the margarine out of the freezer, hold it in the foil, dip it into the flour, then grate it on a coarse grater placed int eh bowl over the flour. Keep dipping the margarine down into the flour to make it easier to grate. At the end you will be left with a lump of grated fat in the middle of the flour, so now take a palette knife and start to cut it into the flour – don’t use your hands – until the mixture is crumbly. Now add enough wáter to form a dough that leaves the bowl clean, using your hands. Pop the dough into a polythene bag and chill it for half an hour – this time in the main body of the fridge.
[I cook this pastry 25mins in the oven with the pre-cooked steak & kidney as a filling].