Add the 2 pounds lean ground beef and 1 medium sweet onion, (small diced) into a large skillet over medium-high heat, cook and break up the beef into crumbles. Continue to cook until the onions are softened, and there is no pink left in the beef, about 10 minutes.
Drain any excess grease. Add the 4 cloves garlic (minced) and cook until fragrant (about 30 seconds.) Take off the heat.
Spray an 6-8-quart oval slow cooker with cooking spray and place the meat mixture into the slow cooker.
Add the 12 ounces frozen mixed vegetables, 2 cups water, 2 (.87 ounce) packets brown gravy mix, ¼ cup tomato paste,1 teaspoon Italian seasoning and ½ teaspoon black pepper into the cooker, and stir well to combine.
In a large bowl, stir together the 4 ounce packet instant mashed potatoes and 2 cups boiling water until thickened. Smooth out the mashed potatoes on top of the meat mixture.
Cook on low for 4-6 hours and serve immediately. Add a sprinkle of dried parsley flakes, if using, then serve!
