Preheat the oven to 350° F. Line two sheet trays with parchment paper and set aside.
In a large skillet over medium heat melt 4 Tablespoons unsalted butter. Once the butter is hot, add 1 small sweet onion, small diced and allow it to cook until translucent, about 8 to 10 minutes, stirring occasionally.
Add 5 cloves garlic, minced and cook until fragrant, about 30 seconds.
Add 4 Tablespoons all-purpose flour and stir it to cook for 1 minute.
Slowly stream in 1 cup chicken stock while whisking constantly.
Whisk in 1 1/2 Tablespoons Better Than Boullion chicken base.
Again, while whisking constantly, add 1 cup milk and 2 cups heavy cream.
Whisk in 1/2 teaspoon dried Italian seasoning and 1/4 teaspoon black pepper.
Allow to simmer until thickened, about 3 to 5 minutes. Take off the heat.
Add 4 cups small diced cooked chicken to a large bowl, stir in 1 cup of the sauce until evenly coated, set aside. (Note: you’ll be using the rest of the sauce to serve on top when they are done baking.)
Working with one of the 2 sheets puff pastry, thawed at a time, roll it out on a lightly floured work surface into a 12×12 square. Cut into 4 sections.
Add ½ cup of the filling per section. Lightly dampen the outside edge of the pastry with water.
Fold up the sides around the filling and pinch the seams so they form a little package. Repeat with all of the filling and puff pastry.
Place the pouches on the parchment-lined baking sheets.
In a small bowl, whisk together 1 large egg and a splash of water until well combined. Brush the pouches with the egg wash.
Bake for 30-32 minutes until golden brown.
When the pouches are almost done baking, warm up the sauce on the stove top. If you think it has become too thick, you can add a splash of more stock to loosen it up.
Serve the pouches with the remaining sauce on top.
