In large pot, fill half way with water. Bring to boil.
Add carrots, onion, celery, potato and chicken breasts.
Cook for about 20 minutes.
Meanwhile, in medium saucepan, melt 1 ½ tbsp.
Stir in half of the flour and start to slowly adding in the ½ cup of milk.
Whisk in chicken broth.
Stirring frequently, add in remaining flour and milk. Simmer over medium heat until sauce begins to thicken. You may need to add more flour depending on desired consistency.
Add in poultry seasoning, onion and garlic powder, pepper, and desired amount of fresh parsley.
Allow sauce to thicken.
Drain cooked chicken and veggies.
Add into the sauce mixture and stir until mixed well. Allow to cook for a few minutes, stirring frequently to allow flavors to incorporate.
Using 4 ramekins, add enough pot pie filling reach the rim.
Cut puff pastry into 4 pieces large enough to cover top of ramekins and fold over.
Using egg wash and pastry brush, wash one side of the pastry puff. Place egg wash side down on ramekin and pinch sides of ramekin to hold in place.
Add additional egg wash to top of pastry puff.
Place ramekins on baking sheet and bake in oven for about 10 minutes.
Reduce temperature to 400° and bake for an additional 10-15 minutes or until tops are golden brown.