Start by making the pastry by sifting the flour in to a large mixing bowl and rubbing the butter and lard until the mixture resembles a sandy texture. Make a well in the middle and add the egg and mix with 1 tbsp. of cold water until the pastry begins to bind. Empty on to your work top and gently bring together to a smooth ball. Try not to over work the pastry. Wrap in cling film and then place in to the fridge until required.
Pre-heat the oven to 200C / 180C fan. Heat a large pan over a medium to high heat and add the olive oil followed by the onions and cook until soft and lightly coloured. Add the mince and continue to fry until the mince has browned off.
Add the grated carrot and courgette and stir in to the mince mixture followed by the peas and thyme and cooked for 2 minutes.
Take off the heat and mix the tomato puree, Worcester sauce, stock cube and 200 ml of hot water to make a paste. Place the pan back on the heat, add the flour and stir followed by the paste. Mix well and season to your liking.
Place the mix to the side and take the pastry out of the oven. Grease a 20 cm cake/pie tin and then cut off 2/3 of the pastry. Place the 1/3 of pastry to the side as this will be your lid.
Roll out the larger piece of pastry on a floured surface to a large round than that of your pie tin. Line your tin and press gently in to the sides followed by adding the pie mixture.
With the remaining pastry roll out to the size of the pie tin, lightly brush the base side of the pie with water and lay the pie lid on top. Crimp the lid to the base with your thumb and forefingers or a fork and then cut off the edges.
With the trimmings, roll out and cut out some leaves or shapes that you desire for decoration. Brush the top of the pie with the remaining egg, cut a cross in the middle and place the decoration on top and brush with egg.
Finally sprinkle with sea salt and bake for 40 mins until golden and crisp.
Remove and allow to rest for 5 minutes before cutting and serving with some creamy mashed potato such as colcannon and your favourite vegetables.