Assemble another double boiler.
In a heat proof bowl, add the egg whites, sugar, and corn starch. Stirring constantly but slowly, cook on medium heat on the double boiler until the sugar is fully dissolved. Test by feeling the spoon or whisk, and rubbing some of the meringue between your fingers. You should not be able to feel any sugar. crystals.
Move the meringue mixture to your electric mixer and whip, starting on a low speed and working your way up to full speed, until the meringue is in stiff peaks that stand on their own.
Spread the stiff meringue on the lemon curd, using a spatula or spoon to create waves. Torch with a kitchen torch or broiler until browned.