Preheat grill to high heat. In a large skillet, brown meat over medium-high heat. Stir in seasonings, tomato sauce and beans and set aside. Begin assembling packets. Spray each piece of foil with non-stick cooking spray. Place about ¾ cup potatoes in the center of each piece of foil. Top with 1 teaspoon of butter and a pinch of salt. Top with ½ cup of taco meat and a sprinkle of cheese. Repeat with remaining 5 pieces of foil and ingredients. Bring the two sides up and fold down twice. Then fold in both ends, twice, to seal the packet. Grill for 25-30 minutes, until the potatoes are tender. Serve with sour cream, salsa, and avocado.