Preheat oven to 375°F
Begin by sautéing the onion, then add the ground beef, and season it with salt and pepper to taste.
Add in the paprika, chili powder, Worcestershire sauce, and beef stock. Allow the mixture to simmer until the meat is fully cooked and the flavors have melded together.
Add the ketchup and Dijon mustard (or for a spicier twist, consider using ½ tsp of horseradish in place of the mustard). Let the mixture cook for an additional 5 minutes.
Finally, stir in the frozen peas, carrots, and corn mix. Cook the entire mixture for another 5 minutes.
Next, create a bed of your favorite mashed potatoes on top of the beef and veggie mixture. (CLICK FOR MY EASY MASH RECIPE) Lightly brush an egg wash over the potatoes and then use a fork to make lines across the top. This will create a delightfully crunchy crust when the dish is baked.
Bake the dish in the oven at 375°F for 25 minutes, and then turn the oven to broil and cook for an additional 5 minutes.
Once finished, let the dish cool for 10 minutes before serving.