Grill chicken breasts until cooked through. Allow to cool.
Grill diced onions until transparent. Set aside.
Dice chicken into 1/2" cubes.
Preheat oven to 350.
Grease a 11x13" baking dish.
Unroll 1 can of crescent rolls and pinch perforations to seal into a sheet. Press into bottom and up sides of prepared disk. Don't worry if sides do not go all the way up.
Bake for 20 minutes or until crust is light brown.
Allow to cool.
In a large skillet, combine chicken cubes, diced onion, water, potatoes and peas and carrots.
Stir and cook over medium heat until ingredients are warm (5-10 minutes).
Add soup and poultry seasoning and continue heating for another 5 minutes. If sauce looks too thick, slowly add a little more water until desired consistency is reached.
Pour chicken mixture over baked crust and spread evenly.
Unroll other can of crescent rolls and pinch perforations to seal into a sheet. Place over top of chicken mixture and press into sides of dish.
Bake for 25 minutes or until top is golden brown.