SAUCE: In nonstick skillet, heat 2 teaspoons oil. Add garlic, flour and chili powder, mixing well. Add chicken broth and simmer until thickened like gravy, 10 to 15 minutes.

Wrap tortillas in foil and place on lower shelf of oven. Heat thoroughly to prevent from cracking. Cut up chicken in small chunks and mix with 2 teaspoons of chili powder and a little broth, just enough to lightly coat.

Fill each tortilla with cheese, onions, yogurt and chicken. Roll up and place in 11 x 13 inch baking dish (coat bottom with thin layer sauce). Pour sauce over enchiladas covering all of them. Garnish with cheese and black olives. Bake at 350 degrees for 30 minutes.