This is great for cookouts. 
1.  Slice vegetables of choice into 1/8 - 1/4 inch pieces (we like red, green and yellow peppers, onions, potatoes           (sometimes we add mushrooms)
2.  Mix together in large bowl and season with onion salt, garlic salt and pepper to taste. 

3.  Tear foil into 8 inch strips and spray with non-stick cooking spray.

4.  Place vegetable mix onto foil and top with a pat of butter.

5.  Fold foil up on all sides and crease in center creating a water tight sealed pouch.

6.   Place on grill and cook over medium heat for 15 to 20 miniutes.  (be sure not to have too high a temperature as vegetables will burn.)

No mess when you're done!