Well, I whisk the egg whites until stiff, then slowly whisk in the sugar until it's firm and glossy, doesn't fall off the whisk is my test.
Slice the cake (have you ever tried Xmas cake minus the icing?) and then arrange on a baking parchment-lined baking sheet. Make it round, the same size as the top of the ice-cream bowl.
Press these together well to make sure there aren’t any gaps.
Lift ice cream out of bowl, remove cling film and turn onto the cake.
Spread the meringue evenly over the ice cream and cake, making sure there are no gaps! Then bake some 4-5 mins until you are happy with the colour.
A stiff glass or two of a Tokaji dessert wine 5* or 6*(even better) goes really well.