Brown ground meat in large skillet or pot. Add frozen veggies and 1/4 cup of water. Cook until veggies are tender. While meat mixture is cooking boil water in pot and make mashed potatoes out of potatoes. (I like to add sour cream to my mashed potatoes, you can also use instant potatoes.) When meat and potatoes are done put meat mixture into casserole dish and spread potatoes on top. Sprinkle cheese on top and cook in 300 degree oven until cheese is melted.