HEAT oil in large skillet on medium-high heat. Add chicken; cook 8 min. or until chicken is cooked through, stirring occasionally.

ADD broccoli; cook and stir 5 min. or until heated through.

STIR in Velveeta and milk. Reduce heat to low; cook 3 min. or until Velveeta is completely melted, stirring frequently. Spoon over the potatoes.