Method

To make the pastry, mix the flour & salt in a large bowl. Grate the frozen Dromona butter directly into the flour (use a box grater with large holes). Toss gently to coat the butter strands with flour.

Gradually add ice-cold water, mixing with a knife until the dough comes together. Turn onto a floured surface and form a rough dough (don’t over-knead—it should look streaky with butter). Flatten into a rectangle, wrap, and chill for 20 minutes.

Roll the dough into a long rectangle, then fold the top third down and the bottom third up like a letter. Turn 90°, roll again, and repeat the fold. Do this three times, chilling for 10 minutes each time.

For the chicken & leek filling

In a pan, melt Dromona butter over medium heat. Add leeks and cook gently for 8 – 10 minutes until soft. Stir in garlic and sprinkle in flour; cook for 1 – 2 minutes. Slowly add chicken stock, milk and then cream, stirring to make a smooth sauce. Stir in mustard and tarragon, and season with salt & pepper.

Add chicken, then simmer gently until thickened. Cool slightly.

Assemble & Bake

Preheat oven to 200°C (180°C fan)/ Gas mark 6

Roll out your pastry to fit your pie dish. Spoon in the creamy chicken and leek filling. Brush the filo squares with melted butter, arrange them on top of the pie, and bake for 30 – 35 minutes until golden, flaky, and bubbling.