Cut the fish into 1 1/2-inch cubes. With a sharp knife or vegetable peeler, remove strips of peel from two of the lemons, leaving the white pith behind. Cut the other two lemons into wedges for serving and set aside.
Alternate threading fish cubes and pieces of lemon peel on each skewer. Arrange on a plate and liberally sprinkle with olive oil, salt, and pepper.
Light a charcoal grill and allow the coals to burn until covered with gray ash or heat a gas grill to medium. Cook the kebabs, turning frequently, for 10 minutes. Serve with the lemon wedges and fresh chervil or parsley.