Follow these steps for a perfectly structured, creamy casserole.

Phase 1: Preparing the Meat and Sauce

1. Brown the Meat: Preheat the oven to **$350^\circ\text{F}$ ($175^\circ\text{C}$)**. In a large skillet or Dutch oven, heat the **olive oil** over medium-high heat. Add the **ground beef and diced onion**. Cook until the meat is browned and the onion is soft. Drain off all excess grease thoroughly.
2. Season: Reduce the heat to medium-low. Stir in the **minced garlic** and the full packet of **taco seasoning**. Cook for 1 minute until fragrant.
3. Create Cream Base: Stir in the **softened cream cheese** until melted and coating the meat. Add the **cream of chicken soup** and the **enchilada sauce**. Stir until the sauce is completely smooth and homogeneous. Taste and adjust salt and pepper.

Phase 2: Layering the Casserole

4. Tortilla Prep: Lightly grease a 9×13-inch baking dish. Slice 6 of the **tortillas** into strips or tear them into rough pieces.
5. **First Layer (Tortillas):** Lay the torn or stripped tortillas in the bottom of the prepared dish, covering the base as much as possible.
6. **Second Layer (Meat & Cheese):** Spread **half of the meat and sauce mixture** evenly over the tortilla layer. Sprinkle with **1 cup of shredded cheese**.
7. **Third Layer (Second Tortilla Layer):** Take the remaining 6 whole tortillas. Arrange them over the meat mixture to form a continuous second layer.
8. **Fourth Layer (Meat & Cheese):** Spread the **remaining half of the meat and sauce mixture** over the second tortilla layer.

Phase 3: Baking and Serving

9. **Final Topping:** Top the casserole with the remaining **1 cup of shredded cheese** and the optional **black olives**.
10. **Bake (Covered):** Cover the baking dish loosely with aluminum foil. Bake for **20 minutes**.
11. **Bake (Uncovered):** Remove the foil and bake for an additional **10 minutes**, or until the sauce is bubbly and the cheese is completely melted and lightly golden.
12. **Rest and Serve:** Let the casserole **rest for 5–10 minutes** before cutting and serving. Serve with sour cream, salsa, and pickled jalapeños on the side.