Double line two 6''/15cm cake tins with cling film, using enough to generously hang over the edge. Press the cling film to the inside of the tins.
To make the ice cream pour the condensed milk (freeze the 2nd half of the tin for the next batch of no churn ice cream) into a pan, add the chocolate and gently heat until the chocolate is melted. Remove from the heat and allow to cool. Fold in the yoghurt.
Pour the cream into a bowl and whisk with an electric mixer until it holds a peak. Add in the milk and whisk again briefly. Fold in the condensed milk and chocolate mixture. Once mixed pour into the prepared tins, smooth with a spatula, loosely cover with the clingfilm and put into the freezer.
Draw a 6'' / 15cm circle as a guide on a piece of paper, and place on a baking tray, under a sheet of baking paper or silicon mat.
With an electric mixer whisk the egg whites until frothy and then add the sugar a spoon at a time whisking between each spoonful. Carry on whisking until the mixture is smooth, white and glossy and holds a peak.
Spread about half of the mixture out onto your template circle, smoothing it into a flat disc. Use a teaspoon to make mini walnut sized meringue with the remainder of the mixture.
Place in an oven pre heated to GM2 / 300F / 150C, immediately turn the oven down to GM1 / 275F / 140C. Cook for about 40 – 50 mins. When the meringue is hard and sounds hollow when lightly tapped, turn the oven off and allow to cool inside the oven.
Place one of the discs of chocolate ice cream on a pretty plate or cake stand, top with the meringue disc and the second disc of ice cream. Gently press down to lightly crush the meringue. Top with chocolate truffles and mini meringues. Serve immediately.
Crush the meringue in any leftovers, decant into a tub and return to the freezer and serve as ice cream.