Instructions
Preheat oven 425°F. Coat a 9- X 13-in baking dish with cooking spray.
In a large nonstick skillet, heat oil over medium heat. When oil shimmers, add 2 cups onion; cook, stirring occasionally, until translucent, 2-3 minutes. Add mushrooms, zucchini and 1/2 tsp salt; cook, stirring occasionally, until vegetables are softened, 15-20 minutes.
While vegetables cook, make sauce. Put tomatoes, chipotle, remaining 1 c onion, garlic, chili powder, cumin, oregano and remaining 1 tsp salt into a blender; puree.
Transfer cooked vegetables to a medium mixing bowl; stir in chicken and 1 cup tomato sauce.
Spread 1/2 cup tomato sauce in bottom of baking dish; top with 6 overlapping tortillas. Sprinkle with half chicken mixture and 1/2 cup cheese; top with 6 more tortillas, remaining chicken mixture and 1/2 c cheese. Top with remaining 6 tortillas; spread remaining sauce on top and sprinkle with remaining cheese. Bake until golden and bubbling, 15-20 minutes.
Remove from oven; let sit 5-10 minutes. Serve each piece with 1 Tbsp sour cream.
Serving size: 1/12th of casserole and 1 Tbsp sour cream
Nutritional Estimates Per Serving (1/12): 230 calories, 4.5 g fat, 24.6 g carbohydrate, 5.6 g fiber, 22.9 g protein and 5 points plus, 5 SmartPoints