Place both the flours and salt into a large bowl. Add the cold butter and toss to coat the cubes in flour. Use your fingertips to rub the butter into the flour until you have a mostly sandy/breadcrumb texture with some pea-sized lumps of butter remaining. (You can also do this by pulsing the same ingredients in a food processor)

Add the egg yolks and about half of the water. Start to bring it together with your fingertips, gently kneading. Drizzle in more water as needed, a tablespoon at a time, until the dough starts to stick together and feels slightly moist but not sticky.

Smush the dough together into one big ball with your hands then flatten it into a disk shape. Place in a resealable sandwich bag and chill for 1 hour so it can rest.

Let the chilled dough warm at room temp. for a few minutes so it softens slightly. Line a large baking tray with baking paper.

Dust the pastry lightly with flour and roll it out into a circle about 35cm (14 inches) in diameter. It doesn't matter if it is slightly larger than the baking tray at this point. Roll up the pastry around the rolling pin, then unroll over the lined baking sheet.

Roll and tuck the outer 5cm (2 inch) border of the circle under itself to neaten the edge and create a thicker crust, a bit like a pizza! NOTE: You may need to trim the edges of the pastry before rolling up to get it to fit onto the baking tray properly.

Now crimp the edge of the pastry all the way around with your fingertips (see video above for how to do it) OR use the tines of a fork to make impressions all the way around the edge.

Prick the centre of the pastry all over with a fork to prevent it bubbling up when it bakes.

Chill the pastry for 10-15 minutes as your oven preheats to 190 C (170 C fan / 375 F).

Bake for 25-30 minutes until golden brown. Keep an eye on it and use a metal spatula to press down any big air bubbles that may form as it bakes.

Let the crust cool before filling.

Combine the egg whites and sugar in a medium, heatproof bowl. Set over a pot of simmering water making sure the bottom of the bowl isn't touching the water.

Stir constantly until the sugar has dissolved (the mixture shouldn’t feel gritty when you rub some between your fingertips) and registers 71 C (160 F ) on a thermometer.

Remove the bowl from the pan and use electric beaters to whisk until cool, very fluffy and thickened - you should be able to lift up the beaters and form stiff peaks in the mixture which do not sink back into the meringue. Transfer to a piping bag fitted with a wide plain tip (or you can dollop it with a spoon if you don't have piping bags).

When you're ready to serve: Whip the double cream in a large bowl with a whisk until thickened. Fold in the yogurt and icing sugar.

Prep the berries by removing any stalks and cutting up larger berries into slices.

Spread the whipped yogurt cream over the pastry. Top with the berries. Pipe on (or spoon on) blobs of meringue all over. If you have a blowtorch you can use it to toast the meringue blobs but it's not necessary.

Serve!