Pork Tenderloin With Fruit with apricots

1 (1 lb) pork tenderloin, trimmed 1 garlic clove , sliced into 6 thin pieces 1/2 cup apricot preserves (preferably with whole fruit) 1/2 medium lemon, juice[...]

2 tablespoons unsalted butter 2 large vidalia onions or 2 large other sweet onions , sliced 2 tablespoons firmly packed dark brown sugar 2 tablespoons[...]