• Cut the onions in half, then peel them and cut them into 1cm (½") thick half-moon shapes.
• Heat half of the oil in a 15cm or 6" saucepan (not nonstick if possible) over a low heat and add the onions. Then cook gently for 1 hour, stirring occasionally until properly caramelised. Then remove and set aside.
• Cut the steak into 1-1.5cm (½") cubes and season it with the salt and pepper.
• Heat a 20cm or 8" saucepan over a high heat and add the remaining oil.
• Dust the beef with the flour and then brown half of it all over, then remove and set aside. Repeat with the other half of the meat. You may need an extra splash of oil for the 2nd batch.
• Return the other half of the beef to the pan along with the caramelised onions, fresh thyme, the beef stock, Worcestershire sauce and the Marmite, then give it all a stir.
• Reduce the heat to low and simmer for 2 hours, then remove from the heat and allow to cool completely. If you have refrigerated the pie filling, remove it from the fridge around 30 minutes before making the pie.

Instructions For Homemade Short Crust Pastry:

• If you are using homemade pastry, add the flour, salt, beef dripping and butter to a food mixer and pulse to form "breadcrumbs".
• Pour the water for the pastry into the mixer little by little until it forms a ball.
• Remove the and wrap the pastry ball in cling film and chill for at least 3 hours. Remove the pastry from the fridge 30 minutes before using.

Build & Cook The Pie:

• Roll out the pastry until it is 3-4mm (⅛") thick and cut it in half, then cut a piece off large enough to form the lid of each pie.
• Grease and flour two small pie dishes. I use oval pie dishes that hold around 250ml (1 cup) of liquid that are 15cm x 11cm x 3cm (6" x 4½" x 1¼").
• Line the pie dishes with pastry, leaving a very generous overhang.
• Remove the "solids" from the gravy with a slotted spoon and divide it between the two.

  The gravy should be quite thick when cold, and you should not need to add more to the pie. Keep the gravy to be reheated and served poured over the pie.
• Crumble the Stilton cheese over the top of the pie filling.
• Brush the edge of the pie case with water using your finger, then add the lid, and seal by pressing the edges. I use my thumb and work my way around until it is all sealed.
• Trim off the excess pastry; you should have only used half to two-thirds of the pastry.
• Whisk together the egg yolk with the milk and brush over the top, then sprinkle with a little sea salt and cut a cross in the centre of the pie lid.
• Place in the oven and cook for 40-45 minutes at 180°C or 350°F. Allow them to cool for 5 minutes before turning out.
• Whilst the pies are cooling reheat the leftover gravy, if you want to thicken it a little mix half of a teaspoon of cornflour with one teaspoon of water and whisk it into the hot gravy.