1: At least 24 hours in advance, start the piccalilli. Mix the French beans, shallots, onions, cauliflower, cucumber and sea salt together in a large non-metallic bowl. Cover the bowl with clingfilm and leave to stand at room temperature for 24 hours.
2: Meanwhile, put the white wine vinegar, malt vinegar and chilli flakes in a saucepan over a high heat and bring to the boil. Remove the pan from the heat and leave mix on one side to cool.
3: After the vegetables have been in the fridge for 24 hours, rinse them well to remove the salt, then return them to the washed bowl. Combine the caster sugar, mustard powder, turmeric and cornflour in a bowl. Stir in a little of the vinegar mixture until smooth, then add this thin paste to the remaining vinegar mixture in the pan. Bring to just below the boil, stirring, until it thickens slightly. Pour it over the vegetables and blend together well. Leave to one side to cool completely.
4: To make the hot-water crust pastry, mix the flour and salt together in a large bowl and make a well in the centre. Melt the butter and lard with the water in a saucepan over a medium heat. Pour this melted fat and the eggs into the well and mix with a wooden spoon to form a dough. Use your hand to knead the dough around the bowl until it is smooth and silky. Cover the bowl with clingfilm and leave the dough to rest for 1 hour, or until the dough becomes elastic and easy to work.
5: Meanwhile, make the filling. Mix the pork shoulder, bacon, pork belly, sage and thyme leaves, cayenne, mace, the black and white peppers and the salt together in a large bowl. Leave to one side until needed.
6: Preheat the oven to 180°C/Gas Mark 4. Generously grease a deep 25cm springform cake tin with lard. Cut off one-quarter of the dough, wrap in clingfilm and leave to one side to use later for the pie lid. Roll the remaining dough out on a lightly floured surface into a 45cm circle about 1cm thick. Drape the pastry over the rolling pin and unroll it over the pan, then gently ease it down into the pan. Press it down on to the base, but leave the overhang.
7: Fill the pastry case with the filling, pressing it down against the base and side. Roll out the remaining pastry into a 25cm circle 1cm thick. Place it on top of the pie. Dampen the underneath edge and press to seal with the overhang. Use a fork to crimp all around the edge, then cut a steam hole in the centre.
8: Place the pie on a baking sheet and bake for 30 minutes. Reduce the heat to 160°C/Gas Mark 3 and bake for a further 1 ¼ hours.
9: Remove the pie from the oven and brush the pastry with the egg glaze, then return it to the oven and bake for a further 15 minutes, or until the pastry is golden brown and the juices run clear when you stick a skewer into the filling. Transfer the pie to a wire rack and leave to cool completely.
10: When the pie is cool, warm the stock in a saucepan over a medium heat. Do not let it boil. Soak the gelatine leaves in cold water for about 5 minutes until softened. Squeeze out the water, then add them to the warm stock and stir until the gelatine has dissolved.
11: Pour the stock in to the pie through the steam hole, then leave the gelatine to cool and set.
12: Serve the pie cut into wedges with the piccalilli.