Heat a comal or cast iron skillet over medium-low heat. Lightly toast the guajillo, and ancho chilis, flipping frequently until aromatic. Avoid burning them.

Heat the 3 cups of chicken broth. Rinse the toasted chiles, then soak them in the hot broth for 5-10 minutes until fully hydrated.

Heat 2 tablespoons of oil in a large pan over medium heat. Sauté the white onion until softened and lightly browned. Add garlic and cook for 1 minute.

Stir in the tomato paste and cook for 1 minute. Add fresh tomatoes and cook until softened and juices release.

Pour in ½ cup of chicken broth, then stir in the shredded chicken. Simmer briefly to blend flavors and reheat chicken. Season with salt to taste, then remove from heat.

Blend the hydrated chiles with their soaking broth, garlic, Mexican oregano, black peppercorns, and cumin until smooth. Strain if desired or needed for a silky texture.

Heat 2 tablespoons of oil in a saucepan over medium-low heat. Pour in the sauce and simmer gently for 5 minutes, stirring occasionally. The sauce should be smooth, slightly thick, and pourable. If too thick, add more broth; if too runny, simmer to reduce.

Once the sauce has the desired consistency, stir in salt to taste. Remove from the heat. 

Heat ¼ cup of oil in a large pan over medium heat. Lightly fry each corn tortilla for 10 seconds per side until pliable but not crispy. Transfer to a paper towel-lined plate. Pat dry if greasy.

Preheat the oven to 350°F.

Lightly spray a 10×13-inch baking dish (excluding the handles) with cooking spray. Spread a thin layer of sauce evenly across the bottom to coat it completely.

Stuff each tortilla with chicken filling, roll tightly, and arrange seam-side down in the dish.

Pour sauce over the tortillas, coating generously but leaving some edges exposed for a rustic look.

Top with Queso Oaxaca and bake for 20 minutes until bubbly and heated through.

Switch to high broil for 2-3 minutes for a golden top, watching closely to avoid burning.

Serve hot with a salad, refried beans, Mexican rice, and crema Mexicana.