Crafting these mummy pot pies is a two-part adventure: first, creating the delicious, savory filling, and second, bringing our mummies to life with the puff pastry. Follow these steps carefully for a ghoulishly good result.

Part 1: Creating the Creamy Pot Pie Filling

1. Melt and Sauté: In a large Dutch oven or heavy-bottomed pot, melt the butter over medium heat. Once it’s shimmering, add the diced onion, carrots, and celery. Sauté the vegetables for about 8-10 minutes, stirring occasionally, until they become soft and the onion is translucent. This step, known as building a mirepoix, creates the aromatic flavor base for the entire dish.
2. Make the Roux: Sprinkle the all-purpose flour over the softened vegetables. Stir continuously for about two minutes. The flour will coat the vegetables and begin to cook. This process, creating a “roux,” is crucial for thickening the sauce and cooks out any raw flour taste. The mixture will look thick and pasty.
3. Build the Sauce: Slowly pour in the chicken broth while whisking constantly. This is a key step to prevent lumps. Keep pouring slowly and whisking until all the broth is incorporated and the mixture is smooth. Bring the mixture to a simmer.
4. Thicken and Enrich: As the sauce simmers, it will begin to noticeably thicken. This should take about 3-5 minutes. Once it can coat the back of a spoon, reduce the heat to low and stir in the heavy cream, salt, and black pepper. Let it gently warm through for another minute, but do not let it boil after adding the cream.
5. Add the Stars: Remove the pot from the heat. Gently fold in the shredded chicken, cooked ground beef, diced ham, and the thawed pea and corn mix. Stir until everything is evenly distributed throughout the creamy sauce. Your pot pie filling is now ready!

Part 2: Assembling and Baking the Mummies

1. Preheat and Prepare: Preheat your oven to 400°F (200°C). Have six to eight individual-sized ramekins or oven-safe baking dishes (about 10-12 ounces each) ready.
2. Fill the Ramekins: Divide the warm pot pie filling evenly among your prepared ramekins. Fill them almost to the top, leaving a small amount of space to prevent the filling from bubbling over too much. Place the filled ramekins on a large, parchment-lined baking sheet. This will catch any potential drips and make cleanup a breeze.
3. Prepare the Pastry: Gently unfold one sheet of thawed puff pastry on a lightly floured surface. Using a pizza cutter or a sharp knife, cut the pastry into thin strips, about 1/2-inch to 3/4-inch wide. Repeat with the second sheet of puff pastry. You’ll have a big pile of “bandages.”
4. Wrap the Mummies: Take the pastry strips and begin draping and weaving them over the top of each filled ramekin. Crisscross the strips in a random pattern to mimic the look of mummy wrappings. Don’t aim for perfection; a slightly messy, haphazard look is more authentic and spooky! Let some strips hang slightly over the edges.
5. Apply the Egg Wash: In a small bowl, whisk together the egg and one tablespoon of water to create an egg wash. Using a pastry brush, gently brush the egg wash over the top of all the puff pastry strips. This step is essential for achieving that deep, golden-brown color and a beautiful shine.
6. Bake to Perfection: Place the baking sheet with the mummy pot pies into the preheated oven. Bake for 20-25 minutes, or until the puff pastry is puffed up, golden brown, and the filling is hot and bubbly at the edges.
7. Add the Eyes and Rest: Remove the pot pies from the oven. While they are still hot, gently press your chosen “eyes” (candy eyes, capers, or olive slices) into the pastry, peeking out from between the “bandages.” Let the pot pies rest for at least 5-10 minutes before serving. This allows the filling to set slightly and cool down to a safe eating temperature.