Preheat the oven to 350 degrees F.
Grease a 3-quart baking dish.
Evenly spread the tortillas onto two baking sheets.
Bake the tortillas on separate racks in the oven for 15 minutes.
Transfer the tortillas from the oven and let them cool.
While the tortillas are baking, in a large skillet over medium-high heat, add the oil, the onion, the garlic, and the oregano and cook, while stirring, for 2 minutes.
Add the tomatoes, the broth, and the chipotle peppers to the onion mixture and bring it to a boil.
Reduce the heat and simmer the tomato mixture, while stirring occasionally, for 10 minutes.
Stir the chicken into the tomato mixture.
Cover the bottom of the prepared baking dish with the tortillas.
Top the tortillas with the chicken mixture and let it cool.
Cover the casserole and let it chill in the refrigerator overnight.
Preheat the oven to 350 degrees F.
Bake the casserole, covered, for 35 minutes.
Transfer the casserole from the oven.
Make eight indents in the chicken mixture with the back of a spoon.
Crack one of the eggs into a custard cup and then gently pour it into one of the indents. Repeat this until all of the indents contain eggs.
Sprinkle the eggs with the pepper.
Bake the casserole, uncovered, until the egg whites have set and the yolks have thickened, about 10-15 minutes.
Let the casserole stand for 10 minutes.
Serve the casserole topped with the cilantro, the avocado, and the lime wedges.