Heat remaining oil in skillet on medium-high heat. Add mushrooms and onions; cook and stir 8 min. or until onions are tender and mushrooms release most of their liquid. Stir in chicken broth; bring to boil. Whisk in cream cheese product; cook and stir on medium heat 3 min. or until cream cheese is completely melted and sauce is slightly thickened. Return chicken to skillet; cook 1 min. or until heated through, stirring frequently.