Add onions and garlic to reserved drippings; cook on medium-low heat 5 min. or until onions are crisp-tender, stirring frequently. Stir in flour; cook and stir 2 to 3 min. or until bubbly. Gradually stir in broth. Add potatoes; bring to boil on medium-heat. Simmer on medium-low heat 15 min. or until potatoes are tender, stirring frequently.