Heat the olive oil in a frying pan, add the leeks, dried and fresh mushrooms and fry gently until the mushrooms release their juices and until the liquid evaporates.

Add the garlic and fry gently for a further minute.

Leave to cool.

Boil the sweet potatoes for about 10 minutes or until fork tender, drain and mash and leave to cool.

Mix all the filling ingredients together, taste and adjust seasoning.

Preheat the oven to 200C/180 Fan/ Gas Mark 6.

Lightly grease a 12 hole muffin tin

Mix the flour, baking powder, salt, mustard and cayenne together in a bowl.

Put the vegetable fat and water together in a small saucepan and bring to a rapid boil, pour into the flour mixture and mix together quickly to form a soft dough.

As soon as you can handle the dough cut off one quarter and leave to one side.

Divide the remaining mixture into ten pieces and roll each into a ball.

Put one ball into each of ten holes in your muffin tin and, working quickly, mould each one with your fingers across the bottom and up the sides of each muffin hole to make your pie cups.

Roll out the remaining dough and cut 10 lids using a 7 cm pastry cutter.

Fill each pie cup to the brim with filling, pressing it in so that your pies are generous and full with no disappointing airy gaps!

Moisten the top of the pastry with non dairy milk (or water) and press the lids into place.

Glaze with a little almond milk and bake in your preheated oven for 20 minutes.

Carefully remove your pies from the tin, pop them on a baking sheet and back into the oven for 15 minutes so that the sides have a chance to turn crisp and golden as well as the tops!

Serve hot or cool on a wire rack and pop them into a picnic basket!