Preheat your oven to 400 degrees Fahrenheit.
Heat a large oven-proof skillet (cast iron is best) over medium-high heat and add the butter.
Add the onion and garlic and saute them in the butter just until softened.
Add the thyme, basil, rosemary, paprika, and salt and pepper.
Add the flour and stir well until the flour has coated the onion mixture.
Add the white wine and scrape the bottom of the pan, allowing the wine to cook off for about 4-5 minutes.
Add the chicken stock, the cooked chicken pieces, and the frozen mixed vegetables and stir well until a sauce forms.
Add the puff pastry to the top of the filling and tuck the edges of the puff pastry around the edge of the inside of the pan.
Slice a few small vent holes in the top and brush the egg wash (one beaten egg mixed with 1 tablespoon of water) over the top of the puff pastry topping.
Bake at 400 degrees Fahrenheit for about 25-30 minutes or until the topping is an even golden brown.
Let rest for about 5-7 minutes before enjoying.