Melt butter in a large skillet over low heat; add shallots and garlic, and sauté until tender. Stir in sugar.
Add apple, and cook, stirring occasionally, 3 minutes or until lightly caramelized. Add vinegar, drippings, and jelly; cook, stirring occasionally, 6 to 8 minutes. Serve immediately, or chill, if desired; reheat just before serving. Sprinkle with fresh mint, if desired.