01 -  In a large skillet over medium-high heat, cook the ground beef or turkey with diced onion and minced garlic until browned and cooked through, about 7 minutes. Drain excess fat if necessary. 
 02 -  Add mixed vegetables and beef broth to the skillet. Season with salt and pepper. Simmer the mixture for 10 minutes, stirring occasionally. 
 03 -  Transfer the meat and vegetable mixture into a baking dish. Spoon the mashed potatoes evenly over the top and smooth with a spatula. 
 04 -  Cover the assembled dish tightly with foil or plastic wrap and freeze until ready to use. 
 05 -  Preheat oven to 375°F (190°C). Remove cover and bake the frozen shepherd’s pie for 45 to 55 minutes, until heated through and the topping is golden brown.