Kerri’s Chicken, Green Chile, and Tortilla Lasagna

3 skinless chicken breast halves, bone left in
2 cups water
1 teaspoon salt
8 tomatillos, husked removed
2 serrano chiles, stemmed and seeded
1 tablespoon corn oil
1 cup diced white onion
2 cloves garlic, peeled and coarsely chopped
5 Anaheim or New Mexico green chiles, roasted, peeled, and seeded
½ cup fresh cilantro leaves
1 tablespoon fresh lime juice
1/4 teaspoon ground cumin
Salt and freshly ground pepper to taste
1 ½ cups sour cream
2 cups grated Monterey Jack cheese
2 cups grated Asadero cheese
9 (8-inch) flour tortillas, cut into 1-inch pieces
Put the chicken breasts, water, and salt in a large skillet and bring just to a boil. Cover the skillet tightly, lower the heat to simmer, and poach the chicken until cooked through, about 20 minutes. With a pair of tongs, remove the chicken from the liquid and allow it to cool. Add the tomatillos and serranos to the hot chicken liquid, cover, and cook until tomatillos are tender, about 10 minutes. Cool in the liquid.
In a medium skillet, heat the corn oil over medium-high heat; add the onions and then the garlic and cook until soft, 5 to 10 minutes. Put the cooked onions and garlic in a blender; add the cooled tomatillos, serranos, and the liquid in which they were cooked. Puree. Add the green chiles, cilantro, lime juice, and cumin to the blender and puree again. Adjust seasoning with salt and pepper. Stir in sour cream.
In a medium bowl, mix the cheeses together. Shred cooked chicken from the bone and set aside.
Preheat oven to 350 degrees. Spray a 9 x 13-inch casserole dish with vegetable oil cooking spray. Arrange 1/3 of the tortilla pieces in the bottom of the pan; top with 1/3 of the tomatillo/sour cream sauce. Arrange ½ of the chicken on top of the sauce and sprinkle 1/3 of the cheese over the chicken. Repeat layers once. Finish with remaining tortillas, sauce, and cheese. Bake until heated through, bubbly, and lightly browned, about 45 minutes. Allow to sit for 10 to 15 minutes before serving.