Preheat the oven to 90C/200F. Line 2 baking sheets with parchment paper, set aside.

Beat the egg whites and sugar together on medium-high speed in a clean, metal bowl until you have stiff, glossy peaks.

Fit a large piping bag with a star nozzle and if using colouring, use a tooth pick or wooden skewer to make lines of food colouring down the length of the inside of the bag.

Spoon the meringue into the piping bag and pipe small meringue stars on the prepared baking sheets.

Rest for about 10 minutes.

Bake in your preheated oven for 45 minutes. Then rotate the baking sheets and swap shelves around. Bake for another 45 minutes.

Turn the oven off, prop the door open an inch and leave to cool completely inside the oven.

Zest lemons and set zest aside.

Juice lemons and strain to remove any pulp or seeds. Pour into a medium saucepan and heat on low. Leave to reduce down to 125ml of juice.

Pour into a heat proof bowl and add the zest, leave to cool.

Rinse and dry the saucepan. Once it's cool to touch, add the egg, yolk, sugar and salt to the pan, whisk to combine.

Whisk in the cooled juice and add the butter.

Cook over a medium heat, whisking constantly, until the mixture is thickened and coats the back of a spoon.

Strain through a wire mesh sieve to remove zest. Leave to cool completely and store in a jar to chill until ready to use.

Strain the cold lemon cream to remove zest and add cream and sugar to metal bowl and whip until you have soft peaks.

Spoon the cream into a piping bag and pipe a layer at the bottom of three serving dishes.

Crumble 2-3 meringues on top of the cream. Spoon on 2 tsp lemon curd and place 3-4 blackberries on top.

Repeat these layers 2 times, finishing with a final layer of whipped cream and crushed meringue.

Garnish with another blackberry and a meringue.

Serve immediately.