To make the pastry first you slice butter into small chunks and rub it into flour with your fingers until it resembles coarse breadcrumbs. Add egg yolk and sugar and push it all together until it forms soft dough - if it is too crumbly you might have to add some cold water (tablespoon or so). If you have food processor you can mix it all there but you lost all the fun. When the dough is ready, wrap it into clingfilm and put to fridge to rest for about 30 mins.

Meanwhile prepare the plums.. Halve and stone the plums. You need a heavy, solid bottomed metal pie dish or baking tin for this - put it over a low heat and let butter and sugar melt until they form a rich, honey-hued caramel - you have to be careful with this as this mixture is likely to burn very easily so stir and keep an eye on it to prevent that from happening.
When you have caramel, turn off the heat and push the fruit, cut side up, into it. Roll the pastry out and place it over the fruit, patching any holes as you go. Tuck the edges between fruit and the tin and place the cake in the oven (190°C) where you should leave it till the pastry is golden brown and caramel and fruit juices are bubbling over the edge (beautiful sight). That will take 30 - 45 minutes. When it is ready, leave it outside to cool and then turn it out.

Eat.

chocolate orange belling special ...
very aromatic and moist cake for all of those who think that chocolate and orange marriage is made in heaven you need:

125g unsalted butter
100g good dark chocolate, broken into pieces
300g good (unsweetened), thin-cut marmalade
150g caster sugar
pinch of salt
2 eggs, beaten
150g self-raising flour

Put the butter in a heavy bottomed saucepan (or over pan of hot water) to melt and when it is almost all melted stir in the chocolate and stir with a wooden spoon until it all melts.. Now add the marmalade, sugar, salt and eggs and stir until it is all well amalgamated (I love this word) and then beat in the flour bit by bit. Put into buttered and floured springform tin (20cm) and bake for about 45 minutes or until the fork you stick into it comes out clean (you know how that goes..) on 180°C. When it is done, leave it to cool a bit and then pour the juice of one orange into it (adding a bit of Cointreau will not do it harm either). If you are into making it look pretty, slice orange into thin circles (that is a tricky business if your knife is not extra sharp) and arrange them on top of the cake or do something even more tacky if you have too much time till the guests come.