Cook hamburger, green pepper, and onion in a skillet over medium heat until the meat is browned and vegetables are softened. Season with salt and pepper.

Remove the skillet from heat and drain off any excess grease.

Stir in the cream of potato soup until well combined.

Do not add water.

Line the bottom of a deep-dish pie pan with one uncooked pie crust.

Spoon half of the meat mixture into the pie crust.

Sprinkle half of the grated cheddar cheese over the meat mixture.

Repeat layers with the remaining meat mixture and cheddar cheese.

Top with the second pie crust and seal the edges using a fork.

In a small bowl, whisk the egg well.

Brush the egg wash evenly over the top pie crust.

Bake in a preheated oven at 350 degrees Fahrenheit (175 degrees Celsius) for approximately 40 minutes, or until the crust is golden brown.