1. Preheat oven to 350 degrees.
2. In a large bowl, mix together beef, taco seasoning, oats, and egg until well blended. Press into a 9-inch square or round baking dish. Bake for 25 to 30 minutes until cooked through. Drain any excess liquid.
3. While meat cooks, prepare the mashed potatoes as directed on the package, using the water and milk. Mix in sour cream and set aside.
4. Spread thawed vegetables on top of cooked meat. Top with shredded cheese. Spread mashed potatoes on top of cheese. Bake until heated through, about 15 minutes. Serve hot.
Source: Hannaford fresh Magazine, May - June 2012