Pierce sausage with fork. Cook in large skillet on medium-high heat 15 to 20 min. or until browned.
Remove from skillet.
Cut into pieces; set aside.
Add 1/4 cup of the dressing and chicken to skillet; cook 10 min. or until chicken is browned on both sides. Stir in sausage, mushrooms, broth and remaining 1/4 cup dressing.
Dissolve cornstarch in water; add to skillet. Bring to boil. Reduce heat to low; cover. Simmer 15 min. or until chicken is cooked through.