On the stove top, heat a large skillet over medium-high heat and add ground beef, onion, and garlic. Sauté until beef is fully cooked. Drain grease.
Add flour and cook for a minute longer.
Stir in tomato paste, Worcestershire sauce, soy sauce, and beef broth. Cook for 5 minutes or until sauce begins to thicken.
Reduce the heat to low and stir in the frozen vegetables, salt and pepper.
Pour meat mixture into the bottom of prepared slow cooker.
Prepare potatoes according to package directions. Carefully spread 5 cups prepared mashed potatoes on top of the meat.
Place lid on top and cook on low for 5-6 hours or until bubbly.
Remove lid, sprinkle with cheese, then place lid back on top and cook for 10 more minutes or until cheese is melted. If desired, top with fresh parsley.
Notes
We simply use instant mashed potatoes for this recipe out of easy and simplicity, but you are more than welcome to use homemade mashed potatoes it its place!