1 pound boneless, skinless chicken breasts or thighs, cubed
1 1/2 cups diced onion
Pinch kosher salt
1 large clove garlic, minced
1 teaspoon dried oregano
12 (6-inch) corn tortillas, toasted
3 cups shredded queso fresco
Nonstick cooking spray
Heat the oven to 350 degrees F.
Combine the chiles, garlic, chili powder, cumin, chicken broth, tomato sauce, salt and pepper in a medium saucepan and put over high heat.
Bring to a boil then reduce the heat to low and simmer for 15 minutes or until the chiles are soft. Set aside until ready to use.
Heat the vegetable oil in a large skillet over medium-high heat. Sauté the chicken until just cooked through, approximately 7 to 9 minutes. Move the chicken from the pan to a plate or bowl. Add the onions to the same pan along with a generous pinch of salt, decrease the heat to medium-low and sweat for 4 to 6 minutes. Add the garlic and oregano and cook until the onions are tender, 2 to 3 minutes more. Add the chicken back to the pan, stir to combine and remove from the heat.
Halve 3 of the tortillas
Lube a 13×9″ glass baking dish with non-stick spray then dose half a cup of the sauce into the bottom of the dish. (I usually spread it around with a large rubber spatula.)
Dip 4 tortillas (three whole and one cut into halves) into the remaining sauce and lay them into the bottom of the dish. Cut 1 of the tortillas in half to evenly cover the bottom of the dish. (see diagram)
Top this with half of the chicken mixture and 1 cup of the cheese. Repeat layering finishing with the remaining sauce and remaining cup of cheese.
Cover with foil and bake in the middle of the oven for 30 minutes. Then remove the foil and bake an additional 10 minutes, or until cheese on top is bubbly.