Melt 1 teaspoon of unsalted butter in a large saucepan over low heat. Tear the filo pastry into small pieces and cook over medium heat, stirring, until golden and toasted, about 5 minutes. Remove from heat and transfer to a bowl.

Microwave the pistachio cream for 10-20 seconds until melted. Stir and pour over the toasted filo (save 2 tablespoons for decoration). Mix until fully coated and set aside to cool.

Chop 200 grams of unsalted butter into chunks and beat in a large mixing bowl until soft. Mix in 125 grams of light brown sugar and 100 grams of white caster sugar until combined.

Add 2 large eggs to the butter mixture and mix until combined.

In a separate bowl, whisk together 250 grams of self-raising flour, 100 grams of plain flour, 50 grams of cocoa powder, and 0.5 teaspoon of salt. Fold into the butter mixture to create a thick cookie dough.

Fold in 100 grams of milk chocolate chips.

Line a baking tray with greaseproof paper. Break off large heaped tablespoons of cookie dough and flatten them in your palm. Add a teaspoon of the pistachio filling in the middle and wrap the dough around it to form a ball. Repeat until all dough is used, making 12 cookies.

Place the rolled cookies on the baking tin and wrap tightly in foil. Freeze for 90 minutes (60 minutes if in a rush).

Preheat the oven to 200°C fan / 220°C conventional towards the end of the freezing time. Line another baking tray with greaseproof paper and place it in the oven for 5 minutes to heat.

Place 4-5 frozen cookies on the preheated tray, leaving space between each. Bake for 12-15 minutes until firm on the edges but soft in the middle. Allow to cool on the baking tray for 15 minutes.

Microwave the remaining pistachio cream for 10-20 seconds until melted. Drizzle or pipe the melted pistachio on top of the cookies.