Heat oven to 350 degrees F. Spray an 8-inch or 9-inch square casserole dish with
nonstick spray. Cover the bottom of the dish with 4 corn tortillas, overlapping
them if necessary. Sprinkle half the chicken, half the cheese, half the green chiles
and half the scallions on the tortillas.
In a medium-size bowl or large measuring cup, stir together the enchilada sauce
and yogurt until smooth. Pour half of this mixture over the layers in the casserole
dish. Then layer on the remaining 4 tortillas, the chicken and the chiles. Sprinkle
with half the remaining cheese. Pour the remaining sauce over the dish. Sprinkle
with the remaining cheese and scallions.