Directions are as per Taste magazine, April 2009 but I've added my changes after the **.
Preheat oven to 140°C Put 2 x 20cm flan rings (without bases) on baking trays lined with baking paper. Either line inside of rings with strips of baking paper (use a dab of meringue later on to hold the strips of paper in place) or lightly brush the inside of the rings with melted butter and dust with flour. **I didn't have flan rings so just drew 20cm circles on the baking paper and spread out as close to lines as I could. The mixture spread out a little so maybe 18cm circles would've been better but up to you.
Push brown sugar through a coarse sieve. Whip egg whites until soft peaks form, then gradually beat in the brown sugar 1 Tbsp at a time. Continue whisking for 2-3 minutes until thick and satiny. Divide meringue between the flan rings, being careful not to knock out air. Smooth the surface with a knife.
Bake for 1 hour, preferably on the same shelf, otherwise alternate the position of the meringues once or twice during baking. Remove from oven and cool for 10 minutes. Carefully slip a slim sharp knife between meringue and flan ring to loosen, then leave to cool completely.
When cool, put a light cake rack on top of each meringue, invert, then peel off the paper. Loosen from flan ring and remove ring, then turn meringue top side up again. **I was too busy to do any of this and just left them on the baking tray until I assembled it all together.
Melt chocolate with 3 Tbsp water in a microwave, or in a small saucepan over gentle heat, stirring continually. Cool. Whip cream until just thick and holding shape — and this is important — if it is too stiff it will turn buttery by the time the chocolate is folded in (if this happens, let it down with a little liquid cream — it may help). Pour in chocolate and gently fold cream and chocolate together with a large spoon. ** I didn't get all the 'lumps' out of the chocolate (90% melted) and it resulted in lovely crunch throughout the cream. Make sure the chocolate is cool enough that it wont melt the cream.
Put 1 meringue on a cake stand or plate, then spread with chocolate cream filling. Put the other meringue on top and dust with icing sugar. Refrigerate for at least 1 hour before serving, or up to 8 hours (it keeps well, refrigerated, for 2-3 days). ** A dab of cream on the plate will stop the meringue sliding around. As for it keeping I can't promise that as it lasted a total of 3 hours lol.