Step 1

Hold the onion on a cutting board, with the root end facing sideways.  About 3/4 of an inch in from the root, drive a wooden skewer through the center of the onion.  Push the skewer all the way through, so that the flat end of the skewer is next to the onion and the pointy end is as far away from the onion as possible.

Step 2

On one side of the skewer, slice the root end off of the onion.  On the other side of the skewer, leaving about 3/4 inch of onion, slice the onion so that the skewer is going through the center of the slice.

Step 3

Use a knife to cut the part of the skewer that is sticking out of the onion.  Repeat until both onions have been sliced into even slices, about 3/4 inch thick.  Trim the skewers so that there is not excess sticking out of the onion.

Step 4

Brush the slices on both sides with olive oil, season with salt and pepper.

Step 5

Make a two zone fire - coals on one side and no coals on the other.

Step 6

Place the onions on the cool side of the grill and flip and rotate every 10 to 15 minutes until they are golden brown.  The total time will depend on how hot your coals are and how close they are to the fire, but is usually 25-40 minutes. Onions are done when golden and tender.

Step 7

Heat the grill for 5-10 minutes.

Step 8

Lower the burners to low and cook the onions on the low burner, flipping every 10 minutes until golden brown, about 25-40 minutes. Onions are done when golden and tender.