Sprinkle the onions with the kosher salt and place them in a colander for 30 minutes.
Pat the onions dry with paper towels.
Toss onions with the hot clarified butter.
Tear an 18 x 18-inch sheet of aluminum foil. Spread the onions out on one half of the foil. Sprinkle the onions with black pepper. Fold the foil over the onions and fold all edges to create a sealed package.
Prepare the grill. Place the package on direct medium heat and cook 30-40 minutes. Shake and turn the package every 7-8 minutes.
Yield: 2 – 2 1/2 cups