Bring lard and water to the boil in a pan, stirring all the time. Add salt and flour to make a smooth, stiff paste, working with the hands until there are no cracks in the dough. Cover with a cloth and leave for thirty minutes in a warm place. Dice the meat, keeping the fat and lean separate. Cook the pig’s feet in one pint water for one and a half hours to make a stock which will jelly when cold. When the paste is just warm, mould it into a pie casing with a mould, or over a jam jar or cake tin, retaining enough to make a lid. Put the meat inside, in layers of lean and fat alternately, season well and moisten with a little stock. Cover with the remaining pastry, sealing the edges, and making a small hole in the top. Tie a piece of greaseproof paper or foil all round the pie to keep it a good shape. Bake at 350°F, 180°C, gas mark 4 for two to two and a half hours, and leave until cool. Pour more stock through the hole at the top and leave until cold.