In small bowl, mix olives, sun-dried tomatoes, oil, plum tomato and onion; set aside.
On large microwavable plate, arrange tortilla chips in single layer. Top evenly with cheese. Microwave uncovered on High 1 minute. Rotate plate 1/2 turn; microwave 30 to 60 seconds longer or until cheese is melted and bubbly.
Spoon tomato mixture evenly over chips and cheese.