Step 1: Prepare the Vegetables

1. Sauté Aromatics: Heat olive oil or butter in a large skillet or Dutch oven over medium heat. Add the chopped onion and cook until softened and translucent, about 5-7 minutes. Stir occasionally to prevent burning. The onions should become fragrant and slightly golden.
2. Add Hearty Vegetables: Add the diced carrots and celery to the skillet. Cook for another 5-7 minutes, stirring occasionally, until they begin to soften slightly. Cooking these vegetables first helps to release their sweetness and ensures they are tender in the final hand pies.
3. Sauté Mushrooms: Add the sliced cremini mushrooms to the skillet. Cook until they release their moisture and begin to brown, about 8-10 minutes. Stir occasionally. Mushrooms add depth of flavor and a meaty texture, so don’t rush this step. Allow them to brown slightly for richer flavor.

Step 2: Create the Creamy Sauce

1. Add Flour: Sprinkle the all-purpose flour over the vegetables in the skillet. Cook for 1 minute, stirring constantly, to create a roux. Cooking the flour briefly helps to eliminate any raw flour taste and ensures it thickens the sauce effectively.
2. Gradually Add Broth: Gradually pour in the chicken broth, whisking constantly to prevent lumps from forming. Continue whisking until the sauce is smooth and begins to thicken. Adding the broth gradually and whisking diligently is key to achieving a lump-free sauce.
3. Stir in Cream and Seasonings: Stir in the heavy cream or half-and-half, dried thyme, dried rosemary, and ground nutmeg. Season with salt and freshly ground black pepper to taste. Bring the sauce to a simmer, then reduce heat to low and cook for 5-7 minutes, or until the sauce has thickened slightly. Simmering allows the flavors to meld and deepen, and the sauce to reach the desired consistency. Taste and adjust seasonings as needed.

Step 3: Incorporate Chicken and Frozen Vegetables

1. Add Chicken: Stir in the cooked, shredded or diced chicken to the sauce. Ensure the chicken is evenly distributed throughout the sauce.
2. Add Frozen Vegetables: Stir in the frozen peas and frozen corn kernels. Cook for another 2-3 minutes, or until the frozen vegetables are heated through and the sauce is heated through. Adding frozen vegetables at the end prevents them from becoming overcooked and mushy.

Step 4: Assemble the Hand Pies

1. Preheat Oven and Prepare Baking Sheet: Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper or a silicone baking mat. This prevents sticking and makes cleanup easier.
2. Roll Out Pie Crusts: Gently unroll the refrigerated pie crusts. On a lightly floured surface, use a rolling pin to slightly roll out each crust to make them slightly larger, about 12 inches in diameter. This will give you more crust to work with and ensure you have enough to enclose the filling.
3. Cut Circles: Use a round cookie cutter (about 4-5 inches in diameter) or a bowl and knife to cut out circles from the pie crusts. You should get about 6-8 circles from each crust, depending on the size of your cutter and how efficiently you cut. Re-roll scraps to get as many circles as possible.
4. Fill the Circles: Place a spoonful of the chicken pot pie filling (about 1/4 – 1/3 cup) in the center of each pie crust circle. Do not overfill, as this can make them difficult to seal and cause the filling to leak out during baking.
5. Fold and Seal: Fold one side of the pie crust circle over the filling to create a half-moon shape. Crimp the edges with a fork to seal tightly. Ensure the edges are well-sealed to prevent filling leakage. You can also use your fingers to crimp and create a decorative edge.

Step 5: Bake the Hand Pies

1. Place on Baking Sheet: Arrange the assembled hand pies on the prepared baking sheet, leaving some space between each hand pie.
2. Egg Wash and Score: Brush the tops of the hand pies with the beaten egg wash. This will give them a golden brown color and a nice sheen. Use a sharp knife or kitchen shears to cut a small slit or X on the top of each hand pie. This allows steam to escape during baking and prevents the crust from bursting.
3. Optional: Sprinkle Seeds: If desired, sprinkle sesame seeds or poppy seeds over the egg-washed hand pies for added flavor and visual appeal.
4. Bake: Bake in the preheated oven for 20-25 minutes, or until the hand pies are golden brown and the filling is bubbly. The crust should be golden brown and flaky, and the filling should be visibly bubbling at the slits.
5. Cool Slightly: Let the hand pies cool on the baking sheet for a few minutes before serving. This allows the filling to set slightly and prevents burning your mouth.

Step 6: Serve and Enjoy!

Carefully transfer the Chicken Pot Hand Pies to plates and serve warm. These are best enjoyed fresh out of the oven when the crust is at its flakiest and the filling is hot and creamy.