Preheat oven to 180 C (356F or whatever is closest)
Leave frozen puff pastry sheet to thaw on the counter while you make pie filling.
Heat up some oil on a non stick pan, add chopped onions and cook until fragrant
Add chicken mince and cook until starting to brown
Add vegetables and coconut milk
Stir in laksa paste
Taste and add seasonings to your taste, I added a little sugar for some sweetness but it depends on your laksa paste and how it tastes
Cook until chicken and vegetables are thoroughly cooked, most liquid has evaporated and the mixture is of desired pie filling consistency.
Turn off heat and transfer pie filling into a pie dish
Cover with puff pastry
Brush with egg wash
Bake for about 15-20 minutes or until golden. I did have to put on grill for a few minutes to get the golden crust, it might be different for your oven.