Firstly, you need to make the pastry and get it in the fridge.
Put flour, cocoa, icing sugar and almonds in a bowl and add the butter. Rub it in until you have fine breadcrumbs or you can whizz this up in the mixer (which is what I tend to do) – these days I am all about making these things as easy as possible. Add the egg and mix until it just comes together. Wrap it in cling film and pop it in the fridge for about 30 minutes.
Take the pastry from the fridge and roll it out to approximately 2mm thick (so fairly fine) but if its a bit thicker it won’t matter too much and line greased tart tins. Leave a 1 cm edge hanging over the case and put them in the freezer for 20 minutes. I use baking parchment to line the cases and rice or baking beans to blind bake them. Put them in a preheated oven for 15 minutes and remove the paper and rice. Put them back in the oven if the base is a little soft – 2 or 3 minutes. Pull them out and make the filling. When they are cooler trim the edges and take them out of the tins.
Heat the cream in a small heat proof basin over a pan of boiling water or I do it in the microwave, I blast it for 2 minutes, then I add the finely chopped chocolate or buttons to the cream and stir well. Then add the butter and mix it well. Pour in the cases and sprinkle the petals on top …