Meanwhile, in a large skillet, cook onions, covered, in hot butter over medium-low heat about 15 minutes or until onions are tender, stirring occasionally. Uncover; add brown sugar. Cook and stir over medium-high heat about 5 minutes more or until onions are golden. Add apple, pear, cranberries, garlic, rosemary and pepper to skillet. Cook, covered, for 5 minutes, stirring twice. Stir in cranberry juice and dry sherry. Simmer, uncovered, for 2 to 4 minutes or until liquid is reduced by half.