Dice the potatoes.
Place the diced potatoes in a saucepan filled with enough water to cover the potatoes. Bring to a boil then cover with a lid and reduce the heat to simmer for about 3-4 minutes or until the potatoes are slightly tender. Do not overcook the potatoes otherwise they will become mushy.
Drain the potatoes and set aside.
Microwave the cooked chicken to bring it to room temperature. Then shred the cooked rotisserie chicken and rough chop into small pieces.
Defrost the frozen peas & carrots. Place the the frozen carrots and peas in a bowl. Fill it with some water. Then microwave for 1 minute and 30 seconds. Drain and set aside.
Drain the canned corn and set aside.
Chop the fresh thyme.
Take the pastry sheets and set them on the counter to thaw for about 30 minutes.
Pre-heat the oven at 350 degrees.
In the meantime on medium-high heat melt 1/3 cup of butter.
Add in 1/3 cup of All Purpose Flour.
Also add in 1/2 teaspoon salt, 1/8 teaspoon garlic salt and 1/8 teaspoon black pepper.
Stir it all together for a minute to cook off the flour.
Then slowly pour in 1 3/4 cups of chicken broth a little at a time while constantly stirring.
Then pour in 1/2 a cup of of heavy cream and stir.
Bring to a boil then turn of the heat.
Add in the peas and carrots.
Add in the corn.
Add in the potatoes.
Add in the chicken.
Lastly add in the thyme. Then set the filling aside and let cool to thicken.
Cover a baking sheet with some aluminum foil. Then fill 3 pot pie pans with the filling divided equally among them.
Place one of the pot pie pans onto a pastry sheet facing down and trace around it with a knife leaving about 1/2 an inch space.
There are only 2 sheets in a box of frozen puff pastry so after cutting out 2 circles, use the scraps to make the last circle. Gather the scraps and use a rolling pin to flatten the dough out. Be sure to flour your work space and your rolling pin so that the dough will not stick to it.
Crack 2 eggs into a small bowl and whisk. Brush some egg wash onto the edge of the pans .
Place the cut out pastry sheet over the filling and wrap the edges of the pan with the pastry sheet. Cut slits into the top of the pies.
Brush some egg wash onto the pies.
Place in the pre-heated oven on the second level. Bake for 30 minutes then rotate the baking tray so that the pies will brown evenly.
Then bake for another 25 minutes. TURN OFF the heat and leave the pies in the oven with the door closed for another 10-15 minutes.
Remove the pies from the oven and let them cool slightly to allow the sauce to thicken.
Then serve while still warm.