In a large skillet, heat olive oil over medium heat. Add the lean ground beef, turkey, or chicken, and cook until browned for 5-6 minutes. Mix in taco seasoning and optional veggies. Stir for another 2 minutes and remove from heat to cool slightly.

On a floured surface, roll pie crusts to 1/8 inch thick. Use ghost-shaped cookie cutters to cut out shapes. Gather scraps, reroll, and continue cutting.

Place half of the ghost-shaped pie crusts onto lined baking sheets. Spoon taco filling onto centers, and sprinkle cheese on top.

Cover each filled pie with matching ghost shape, seal edges with a fork.

Whisk egg with a splash of milk or water. Brush the mixture over tops of the pies.

Preheat oven to 425°F (220°C). Bake pies for 10-14 minutes until puffed and golden brown.

Allow to cool for a couple of minutes before serving with fresh salsa or creamy guacamole.