Preheat the oven to 160'C.
Whisk the egg whites with 150g caster sugar and the food colouring. Whisk until you have a stiff and glossy meringue mixture.
Place the icing sugar and the almond powder in a blender. Blitz and then sieve this mixture into a bowl to ensure that you have a very fine, lump-free powder.
Incorporate the dry ingredients into the meringue mixture. Use a spatula to cut and fold the mixture until is smooth, shiny and ribbon-like.
Fill a piping bag with the macaroon mix and pipe the macaroons onto a lined baking tray.
Leave the macaroons to dry slightly for 15 minutes at room temperature and then bake in the preheated oven for 10-15 minutes.
Place the milk in a saucepan and bring to the boil.
Place the egg yolks, caster sugar, flour and the pistachio paste in a bowl and whisk well.
Once the milk is boiling, add it little by little to the egg yolk mixture. Return the mixture to the pan and whisk over a medium to high heat for 3 minutes until it has thickened significantly. Transfer this mixture to a tray lined with clingfilm and chill in the fridge.
Whip the double cream until thick. Slice the strawberries.
When the pistachio cream is cold, whisk it until smooth and then gently fold in the whipped double cream. Transfer to a piping bag and keep cold.
Fill half of the macaroon shells with the pistachio cream then add a couple of slices of strawberry. Top with a second macaroon shell and serve.
«The macaroon shells can be frozen once they are cooked. Make sure they are completely cold before you wrap them up to go in the freezer. Any heat will create condensation that will make the shells soggy when you want to use them.»