Prepare Meringues (can be prepared days in advance):

1. Preheat the oven to 110°C (100°C fan forced)
2. In a clean, dry bowl and with an electric beater or stand mixer with whisk attachment - whip egg whites until stiff peaks form on medium speed (this is where your egg white peaks stand up and hold on their own when you remove the whisk).
3. Increase speed of beater and gradually add caster sugar, one tablespoon at a time until combined and mixture is glossy and thick.
4. Sift your icing sugar, and split into three lots. Add one lot of sifted icing sugar at a time and gently fold into the mix until just combined and the mixture is smooth and billowy.
5. Spoon or pipe meringue onto a parchment-lined baking sheet. Bake for 1.5 to 2 hours until crisp, and the sound of the meringue is crisp when tapped underneath.
6. Allow meringues to cool *completely* and store in an airtight container until ready to use.

Macerate Strawberries:

1. In a bowl, combine sliced strawberries with sugar. Toss gently.
2. Allow strawberries to macerate for at least 30 minutes - or up to 24 hours - releasing their juices. Stir occasionally.

Whipped Pouring Cream:

1. In a chilled bowl, whip cream until soft peaks form.
2. Add icing sugar and vanilla extract, if using. Continue whipping until stiff peaks form.

Assemble Eton Mess (just before serving):

1. Crumble or break meringues into bite-sized pieces.
2. In tall champagne coupe glasses, or bowl of choice, layer meringues, macerated strawberries, and whipped cream.
3. Repeat the layers until the glass is filled, finishing with a dollop of whipped cream and a strawberry slice for garnish.