Melt the chocolate in a bowl over a double boiler. Separate eggs. Beat egg whites with a pinch of salt to stiff snow, slowly pour in half of the sugar. Beat the egg yolks with the rest of the sugar over the water bath until white frothy. Fold in the slowly melted chocolate, then the cocoa. Carefully fold in the egg whites. Pour the mousse into dessert glasses and chill for about 3 hours. Sprinkle with cocoa or chocolate shavings and serve one strawberry cut into slices per glass.
Alternatively: Pour the mousse into a piping bag, squirt into small glasses and sprinkle with the grated chocolate.
Gag: fill the cracked, washed-out eggshells with the mousse and serve in egg cartons; makes 12 eggshells