1. Preheat oven to 425°F.
2. In a skillet over medium-high heat, brown ground meat. Stir in taco seasoning, tomato sauce and beans; set aside.
3. Lay out six 12-in. long pieces of aluminum foil; spray each piece with non-stick spray.
4. In the center of a piece of foil, place 1 c. of sweet potatoes, 1 tsp. butter, 1/8 tsp. salt, 1/4 c. spinach, 1/3 c. taco meat and 1/4 c. of cheese.
5. Fold sides of foil in over the mixture; fold the top and bottom ends of the foil inward and seal. Repeat with remaining foil and ingredients.
6. Place packets on rimmed cookie sheet; bake until sweet potatoes are tender, about 25 min.
7. Serve with sour cream or guacamole.
* Winner in the 2011 Sweet n' Healthy Blogger Recipe Contest; Perry's Plate