In a medium to large skillet add 3 tablespoons of olive oil.
Season your chicken with salt and pepper and add to the skillet, and cook until chicken is no longer pink
Remove chicken from pan and allow to cool.
Once cooled, dice chicken to roughly the same size as the other vegetables and then place to the side.
In the same skillet, add onions and garlic and cook over medium heat until the onions begin to become translucent. You may need to add an additional tablespoon of olive oil if the pan became dry from the chicken.
Add all of the fresh vegetables to the pan, carrots, potatoes, celery.
Add the rosemary, thyme, sage to the vegetables.
Add the white wine to the pan and stir the vegetables. Note, I would scrape the bottom of the pan to get all of those great flavors.
Cook until vegetables begin to soften.
Push the vegetables to the side of the pan to give you a little space to see the bottom of the skillet.
Add your butter to the open space of the pan and add your flour.
Cook your flour for a minute or so, just until the flour begins to brown. Stirring throughout this step.
Add the chicken broth a little at a time. The chicken broth with begin to thicken into a gravy. Continue to add the broth until you get the consistency that you desire.
I would recommend to taste your filling. At this time you can add some additional rosemary, sage, thyme or salt and pepper.
Take off of heat and allow to cool a bit.
Following the directions on the pie crust packaging, place the pie crust into a 9 inch pie pan.
Add the cooled pie filling to the pie pan.
Take a little water and moisten the edge of your pie crust. This will help the top crust adhere.
Place the top crust over the filling and begin to seal the edges of the crust together.
Cut 3 to 4 vent slots into the top crust. This will help the steam escape.
Bake at 375-400 until the crust becomes golden brown.
Allow to cool for approximately 15-20 minutes before cutting into the pie.