Gently fry the leeks in the butter until softened. Add the mushrooms, mace and thyme, and turn up the heat a bit to soften the mushrooms and drive off any liquid that comes out of them. Stir in the potato for 2 mins, followed by the lentils, chestnuts and cream. Cook for 2 mins more, then take off the heat and stir in the 4 tbsp cranberries.
To make the pastry, put the flour and suet in a food processor with 1 tsp salt. Whizz together until you can’t see any big suet lumps, then keep pulsing while you add the milk, a spoon at a time, until the pastry comes together.
Roll out a quarter of the pastry on a lightly floured surface, then use 4 individual pie dishes to cut 4 pastry lids – we used 4 x 250ml ramekins. Use a small star cutter to cut out a star from each lid, then keep stars and lids covered with cling film.
Cut 4 strips of baking parchment and use a little butter to stick one in each pie dish, so the ends of the strips stick outeach side to help you remove the pies when baked. Gather lid scraps with the remaining pastry and divide into 4 equal pieces. Roll out each to £1 coin thickness and use to line each pie dish with an overhang. Divide the filling between the dishes. Top each with a lid, and roll down the overhang to meet the lid. Use a fork’s prongs to press and seal edges. The pies can now be covered and chilled for up to 24 hrs before baking.
To bake, heat oven to 220C/200C fan/ gas 7. Brush each pie with beaten egg and bake for 30 mins. Lift pies from dishes and sit directly onto a baking sheet. Mix 20 cranberries with the redcurrant jelly and divide between the star holes on top. Brush pastry stars with beaten egg, add a small thyme sprig to each, then add to the pie baking sheet and put back in the oven for 5-10 mins, until pies and stars are golden and crisp. Top each pie with a star and serve.