Chicken-Enchilada Casserole

1 c. nonfat plain yogurt
1 c. cottage cheese
2 cloves garlic, peeled
2 tsp. chili powder
2 tsp. sugar
2 tsp. cornstarch
1 T. butter
1/4 c. all-purpose flour
1/3 c. water
2 c. low sodium chicken broth
1 (4oz.) can green chiles, diced
12 corn tortilla, cut into 1-inch slices
2 c. chicken, cooked and cubed
1 onion, chopped
1 c. Monterey Jack cheese, shredded

Preheat oven to 400. In a blender or processor, puree yogurt, cottage cheese, garlic, chili powder, sugar and cornstarch. Set aside. Melt butter in a 2-quart pan over medium-high heat. Add flour and water, stirring until just bubbly. Whisk in broth. Bring to a boil, stirring. Remove from heat. Let cool 5 minutes. Whisk yogurt mixture into flour mixture and stir in chiles. Cover bottom of a 9 X 13-inch baking dish with 1/3 of the mixture. Scatter half of sliced tortillas over the mixture and top with chicken, onion and half of Jack cheese. Spread half of the remaining yogurt mixture, tortillas, last of the yogurt mixture and top with remaining cheese. Cover tightly with foil and bake for 30 minutes. Uncover and return to oven for 20 minutes, or until golden and firm.
Serves 8.