Beat the egg whites until stiff, adding 150 g sugar. Continue beating until a smooth, firm, shiny mixture is obtained. Sift the starch on top, add vinegar and fold in. Line a baking tray with baking paper. Place the beaten egg whites in 8 portions on the baking tray in a dome-shaped form with a tablespoon. Press a small hollow into each portion with a teaspoon. Bake in the preheated oven for approx. 45 minutes, then reduce the temperature if necessary (electric oven: 100 °C/ circulating air: 75 °C/ gas: not suitable) and cover meringue shells with aluminium foil. Switch off the oven. Let meringue dry overnight
Chop the chocolate coating. Heat the cream (do not boil!), remove from the stove. Melt the chocolate in it and stir until smooth. Pour the mixture into a mixing bowl and also chill overnight
Clean and wash the rhubarb, halve it lengthwise and cut into small cubes. Caramelise 75 g sugar in a pot until brown. Deglaze with white wine, add rhubarb and simmer for 1-2 minutes until the sugar is dissolved. Put the compote into a bowl and let it cool down
Whip the chocolate cream with the whisk of the hand mixer until creamy (20-30 seconds), fill cream into a piping bag with a small perforated spout and squirt into the meringue shells (can also be done with a teaspoon). Use a teaspoon to press in small hollows. Put the compote into the hollows and serve
Waiting time approx. 12 hours