Toss pepper strips and onions with 1/2 tablespoon garlic-flavored olive oil.
Cut potatoes into wedges without slicing all the way through.
Alternate place pepper & onion slices into the potato, press down to open up the gaps.
Place each potato on a sheet of foil and top with a tablespoon of butter & seasoned salt and pepper.
Wrap potatoes and place on a propane grill for about 30 minutes on high. Test if they're done by putting a toothpick or fork into the potato. It should be easy to slide in/out.