Ingredients
2 leeks, washed and thinly sliced  
30g butter 
1 egg 
80ml double cream  
125g Welsh cheddar cheese, 40g grated and 40g cut into small chunks 
1 sheet of ready rolled puff pastry 
Salt 
White pepper  

Equipment 
2 small loose bottomed tart tins

Method
Preheat the oven to 200c. 

Keep the pastry in the fridge until you need it because when puff pastry gets warm it is quite hard to handle. 

Start with the leeks.  Put the butter into a frying pan and melt over a medium heat.  When the butter is foaming put the leeks in and stir to coat everything with the hot butter.  Cook the leeks for around 10 minutes until soft and sweet but with no colour.  Put the leeks into a bowl and put into the freezer to cool quickly. 

Take the pastry out of the fridge and unwrap, cutting around a side plate two circles.  Put the pastry back in the fridge or into the freezer for use another time (the leftovers make great sausage rolls).  Take the pastry circles and fit them into the individual tart cases, gently pushing into the flutes, carefully trim the edges and with a fork gently prick the pastry all over - this keeps the pastry from rising while it cooks.  Take a sheet of greaseproof paper, scrunch it up and flatten back out and put it over the pastry and top with either baking beans or rice.  Bake like this for 15 minutes.   

Gently mix the cream, eggs, salt and pepper and eggs and fold through ¾ of the grated cheese.   

After 15 minutes take the tart cases out of the oven and remove the beans and paper and reduce the heat to 180c.  Put the cheese chunks over the base and then the leeks.  Pour the egg mix into the base carefully until almost at the top.  Top with the remaining cheese and bake for 20-30 minutes until they are golden.