Start with the pouring sauce. Melt together the white chocolate and double cream and put aside. Also, to make the meringue, place the egg white and sugar in a bowl over a pan of boiling water and cook for 10 minutes to dissolve the sugar. Allow to cool. Next, cut the panettone into 3 thick slices. Drizzle each with half of the alcohol. Spoon the chocolate ice-cream between the layers and make a dome shaped layer of ice-cream on the top. Freeze overnight or for 3 hours.  When ready to serve, whip the egg white mixture to stiff peaks, spread over the frozen Alaska and use a spoon to peak. Brown using a flame gun or in the oven at 220°C just to quickly brown the edges. Serve immediately decorated with berries, fern and the white chocolate pouring sauce.