Heat the oven to 450° F.
In a large bowl, combine the tomatoes, olives,
parsley, chicken, salt, pepper, vinegar, and the 3 tablespoons oil.
Brush the tortillas on both sides with oil and then put on baking sheets, overlapping if necessary. Bake the tortillas until starting to brown, 2 to 3 minutes. Turn the tortillas and brown the other side, 2 to 3 minutes longer.
Remove the baking sheets from the oven and top each tortilla with an equal amount of the feta cheese. Return the baking sheets to the oven; cook until the cheese is just melting,
1 to 2 minutes longer.
Top the tortillas with the chicken mixture.