Make sure to remove the filo pastry from the freezer at least 2 hours before you need it. Keep it unopened at room temperature on the bench.
Heat a pan on medium to high heat on the stovetop
Add onion and garlic and cook for 1-2 minutes until onion is translucent
Add the diced chicken and cooked until lightly browned
Add the mushrooms and rosemary and cook for 2 minutes, stirring regularly
Add the chicken stock/broth, and let it reduce for 2 minutes
Add the powdered soup mix to the boiling water and add gradually (in 3 lots) to the chicken/mushroom mixture. The soup should thicken the stock/broth to a gravy consistency
Once it has thickened to a gravy like consistency, remove from the heat and let it cool to room temperature before putting onto the flio pastry.
Portion out the chicken: Once Chicken and Mushroom is cooled down, divide it into four equal portions, ready for putting into the filo.
Preheat oven to 180 degrees C/350 F.
Prepare the filo: flatten out 2 sheets of filo. Place chicken in a line lengthways, 1.5 inches from left, leaving an inch at top and bottom (for folding)
Once chicken is placed on the filo, start from the left and fold over once.
Next, fold the bottom to the middle, once, followed by the top. (Kind of like wrapping a Christmas present!)
Finally, roll the filo, making sure the side stay tucked in. Lay the filos onto a grease proof tray with the seam side down so it stays together
Brush over with melted butter so they brown and crisp up, sprinkle a few sesame seeds, and bake in the oven at 180 degrees C/350 F. for 30 minutes.