Use a food processor to turn the digestive biscuits into crumbs - or bash them in a bowl or sandwich bag with the end of a rolling pin
Make the biscuit layer by mixing the digestive biscuit crumbs and melted butter together in a bowl
Add the biscuit mixture to the bottom of your serving glasses (the glasses I used have a 250ml capacity) use the back of a teaspoon to press the crumbs down to compact them. Put them in the fridge to chill while you making the filling
For the lemon filling use a food mixer with a whisk attachment or an electric hand whisk to whip up the double cream with the icing sugar
When the cream is whipped gently mix 130g of the lemon curd into it
Spoon or pipe a layer of the cream filling into the glass, then drizzle some lemon curd over the top, add another layer of cream filling, then drizzle more lemon curd over that
Add a final cream filling layer and smooth the top
To make the Italian meringue put the caster sugar and water in a pan, stir them together then bring to a boil. When the mixture reaches 112C (235F), take it off the heat and pour the sugar syrup into a jug
While the sugar water is coming to a boil, in a stand mixer or using an electric whisk, whisk up the egg whites with the cream of tartar until they reach soft peak stage (foamy and they are just starting to holding their shape on the whisk but not quite)
Then, keeping the mixer running on a medium speed, pour in the hot sugar syrup slowly. Be careful not to let the sugar syrup hit the side of the bowl. Turn the mixer speed up to high and mix until the meringue is white and shiny and holds its shape, and the bowl of the mixer feels cool
Pipe or dollop the meringue on top of the lemon filling. If dolloping, using a spoon and flick it around to give it texture. Then use a kitchen blowtorch to brown the meringue all over
Serve immediately, store any leftovers in the fridge and eat within 2 days