FOR THE MERINGUE
4 egg whites
250g/9oz caster sugar
1 tsp white wine vinega
1 tsp cornflour
1 tsp vanilla extract
FOR THE TOPPING
500g/1lb 2oz strawberries, hulled and halved
200g/8oz redcurrants, stalks removed
3 tbsp icing sugar
350ml/12fl oz double cream
Heat oven to 150C/130C fan/gas 2. using a pencil, mark out the circumference of a dinner plate on baking parchment. Whisk the egg whites with a hand mixer until they form stiff peaks, then whisk in the sugar, 1 tbsp at a time, until the meringue looks glossy. Whisk in the vinegar, cornflour and vanilla.
Spread the meringue inside the circle, creating a crater by making the sides a little higher than the middle. Bake for 1 hr, then turn off the heat and let the Pavlova cool completely inside the oven.
When the meringue is cool, chop 100g of the strawberries. Mix them with half the redcurrants and 2 tbsp icing sugar. Place in a food processor, blitz until smooth, then push the fruit mixture through a sieve. Whip the cream with the remaining icing sugar and spread it over the meringue. Put the remaining fruit on the cream and finally pour the sauce over the whole lot.