Heat 2 tbsp of oil in skillet. Add chicken and season with salt and pepper. Cook until done. Remove from pan and set aside.
Preheat oven to 400°F
In a skillet, sauté onions and garlic until onions are translucent and garlic is fragrant. Stir in frozen peas, corn, carrots and remaining olive oil. Sprinkle flour over vegetables, stirring to remove lumps.
Add chicken broth and milk, letting it come to a boil to reduce and thicken. Season with salt and pepper then remove from heat.
Place pie crust over skillet and seal edges. Brush whisked egg over the crust and cut slits on top to vent.
Bake for 25-30 minutes or until golden brown. Cool for a few minutes, then serve while hot. Enjoy!