1 large yellow onion
1 large red onion
1 1/2 teaspoons olive oil
1/4 teaspoon salt
freshly ground black pepper
1/4 cup balsamic vinegar

Directions:
Preheat the grill to medium-high heat. Peel and
slice the onions 1/2″ thick. Rub the onion slices (trying to keep them
intact) with the olive oil and sprinkle with salt and pepper. Grill the
onions until they are lightly charred and cooked through, about 3 to 4
minutes per side. When the onions are cool enough to handle, chop them
roughly and put then in a bowl. Add the balsamic vinegar.