Cook potatoes in a large saucepan in boiling water to cover 15 minutes or until tender.
Drain and cool.
Cut potatoes into 1/8-inch-thick slices; set aside.
Combine cream cheese and next 3 ingredients in a small bowl, mixing well. Set aside.
Combine tomato, olives, and vinegar in a small bowl; toss gently. Set aside.
Cut 2 circles from each flour tortilla, using a 4-inch round cookie cutter.
Spread cheese mixture evenly over tortilla circles. Overlap potato slices around edges of tortillas to form circles. Coat potato slices with cooking spray.
Place a baking sheet in a 400 oven for 5 minutes.
Remove from oven; immediately arrange tarts on hot baking sheet, and bake 8 to 10 minutes or until hot and tortillas are crisp. Spoon tomato mixture evenly onto centers of tarts; sprinkle with chives.