In a large skillet, cook the ground beef over medium-high heat, breaking it apart as you cook it. Halfway through the cooking time, add the diced onion, garlic, thyme, marjoram, salt, and pepper. Cook for  3 – 4 minutes, or until the meat is cooked and the onion is tender.

In a microwave-safe bowl, place your diced carrots and potatoes with 2 tablespoons of water. Microwave on high for 5 minutes to give the potatoes and carrots to pre-cook before combining with the other ingredients.

Add the carrot and potatoes to the pan of ground beef. Then add the celery, diced tomatoes, peas, and corn. Mix together. Remove the pan from the heat and set aside.

Spray a 9-inch pie pan with nonstick spray. Roll out the pie crusts, and lay one in the pan, using a lightly floured rolling pin to lift and center the crust over the pie plate without tearing it.

Spoon the ground beef mixture into the prepared pie pan. Place the second crust over the top of the pie, and crimp the edges of the crusts together by pinching the dough between your fingers. Repeat all along the edges to seal. Use a sharp knife to cut a few small slits to allow the pie to vent as it cooks.

In a small bowl, beat the egg and brush the top of the pie crust to give it an extra golden-brown color as it bakes.

Place the pie on a cookie sheet to catch any spills during cooking, and transfer to the oven.

Bake for 15 – 20 minutes, or until the crust is golden-brown and the filling is bubbly. If the crust is browning too quickly, cover the edges with foil to prevent burning.