Easy Chicken Pot Pie

1 pound boneless, skinless chicken thighs, cut into 1” chunks
salt and pepper
1 cup all-purpose flour
4 tablespoons butter
1 large carrot, peeled and diced
3 stalks celery, diced
1 small onion, diced
¼ cup frozen green peas
2 cups chicken broth
2 sheets store bought puff pastry, thawed and laid out flat to remove creases

Preheat oven to 425ºF. Season the chicken with salt and pepper. Toss chicken pieces in flour to coat. Shake off excess flour and let sit for ten minutes. Melt the butter in a non-stick skillet over medium-high heat. Add the chicken and let cook for two minutes. Add the carrots, celery and onion, and let cook for two more minutes. Add the peas and stock. Bring to a simmer and adjust thickness by adding more flour or more stock. Season with salt and pepper and remove from heat. Layer one sheet of puff pastry into oven safe pie dish or skillet. Ladle in the filling and top with a second sheet of puff pastry. Fold or pinch together the outside edges of the pie to seal. Cut a few slits into to center of the pie to vent. Brush pie with egg wash and place into a hot oven. Bake for 20-25 minutes or until the pastry is puffed and golden brown.