1 1/2 cups chicken broth
1 cup milk
1/2 cup all-purpose flour
1/2 cup plain yogurt
1 14 oz can diced tomatoes, drained
1 4 oz can chopped green chilis, drained
1/4 cup chopped fresh cilantro
1 tbsp chili powder
1 tsp dried oregano
1/2 tsp ground cumin
Salt & pepper
1 1/2 tsp canola oil
1 large onion, chopped
1/2 red or green bell pepper, seeded and diced
3 cloves garlic, minced
2 1/2 cups diced skinless cooked chicken
12 corn tortillas, cut in quarters
1/2 cup shredded Cheddar cheese

Preheat oven to 375°F.
Bring chicken broth to a simmer in a medium saucepan. Whisk together milk and flour in a small bowl to make a smooth paste. Add to the broth and cook over medium, whisking constantly, until thickened and smooth, about 3 minutes. Remove from the heat and stir in yogurt, tomatoes, chilies, cilantro, chili powder, oregano and cumin. Season with salt and pepper. Set aside.

Heat oil in a large nonstick skillet over medium-high heat. Add onion, bell pepper and garlic. Cook, stirring occasionally, about 3 minutes.

Line the bottom of a shallow 3-qt. baking dish with half the tortillas. Top with half of the chicken and half of the onion mixture. Spoon half of the sauce evenly over the top. Repeat layers with remaining tortillas, chicken, onion mixture and sauce. Sprinkle with cheese and bake until bubbly, 25 to 30 minutes.