Using a large skillet, melt butter and add the flour. Cook for one-minute stirring constantly
Mix in the chicken broth and cook until it thickens, about 3 minutes
Add the green chilies, sliced olives, chicken breasts halves, oregano, chipotle powder, salt, and pepper to the skillet and cook, covered, for 15 mins or until chicken is cooked through
Remove chicken, shred it and return it to the skillet, Stir in the sour cream
Cut the tortillas into bite-size pieces and mix them into the chicken sauce
Top with the shredded cheese, cover, and cook until the cheese is melted and bubbly about 5 to 7 minutes.