PREHEAT oven to 350°F.
COMBINE all ingredients in a 1-quart baking dish, except for chicken. Mix chicken in last to prevent it from falling apart too much. (I also added a handful of shredded chicken and more cheese to the top of the mixture to form a crust.)
BAKE 20 min. or until mixture is heated through. (I broiled the dip for another 5-7 minutes to brown the cheesy crust.)
SERVE warm with crackers, Tortilla chips, or vegetables.