If there were a word more glorious than glorious, I’d use it to describe this. A bit of work and worth the effort!
5 Tbsp. unsalted butter, divided
1 medium onion, diced
½ lb. mushrooms
1 c. chicken stock
1 lg. carrot, peeled and thinly sliced
1 lg. potato, peeled diced (1/2”)
2 Tbsp. fresh chopped parsley
1 Bay leaf
½ tsp. thyme
1 c. frozen peas, thawed (canned won’t work)
1 Tbsp. flour
1 c. ½ & ½
Salt and pepper to taste, be generous
3 c. cooked diced chicken
½ of 17 oz. thawed puff pastry sheet
1 lg. egg
1 Tbsp. milk
Preheat oven to 375. Spray 9 x 13 pan. Heat 2 Tbsp. butter in skillet, add all veggies and seasonings, except peas. Add stock and bring to a boil. Reduce heat to low, simmer 8-10 minutes or until potato is tender. Add peas, cook 2 minutes. Strain, reserving stock. Remove and discard bay leaf, transfer veggies to prepared pan. Heat rest of butter in saucepan, stir in flour and cook 2 minutes- stirring constantly. Add ½ and ½, simmer for 2 minutes. Season. Add chicken to liquid, and reserved chicken stock. Mix in pan with veggies.
Roll puff pastry into 11 x 15 rectangle. Beat egg and milk. Brush mixture around inside edge of pan. Place pastry on top of pan, crimp edges, sealing to side of pan. Brush top with remaining egg/milk and cut six 1” vents. Bake 35 minutes.