Grilled Potatoes in Foil
You can chop, dice, or slice the onion and bell pepper, whichever your prefer.
Cooking spray or margarine can be used in place of butter, if desired.
Sometimes I use minced dried onions when I don't have any fresh. I've also used fresh garlic instead of the powder.
I also think that a splash of Mrs. Dash(R) instead of the salt works great and gives it even more flavor.