Heat oven to 110℃ (fan) / 230℉.
Line two baking sheets.
Beat the egg whites until fluffy and at the stiff peak stage.
4 medium egg whites
Add the caster sugar a spoonful at a time, whisking on a higher speed. Once all incorporated it should be thick and glossy.
105 g caster sugar (superfine sugar)
Fold in a third of the icing sugar with a spatula. Repeat until you have used all the icing sugar.
115 g strawberry milkshake icing sugar
Add a little red food colour gel and swirl through with a skewer or knife so you have swirls of colour.
½ tsp red food colour gel
Use two dessert spoonfuls of mixture to make each meringue.
Bake for 1.5 hours or until the meringues are crisp underneath.
Leave to cool then enjoy.