Preheat Oven & Prepare Dish: Arrange an oven rack in the center and preheat to 375°F (190°C). Lightly grease an 8x8 inch square baking dish.
Prepare Cottage Cheese (Optional Step): If you prefer distinct curds, place the cottage cheese into a fine-mesh colander. Briefly rinse with cold water, allowing the creamy liquid to wash away. Press gently to remove excess moisture and let it drain well while you prepare other ingredients. Otherwise, use cottage cheese directly.
Prep Remaining Ingredients: Ensure green onions are sliced and black olives are drained. Open the can of green chiles (no need to drain unless you strongly prefer less liquid). Have cheeses measured.
Layer Base Ingredients: Spread the drained (or unrinsed) cottage cheese evenly in the bottom of the prepared baking dish. Top with the shredded cheddar cheese. Scatter the sliced green onions, undrained diced green chiles, and drained sliced black olives over the cheese layer.
Whisk Eggs & Seasonings: In a large bowl, crack the 9 large eggs. Add the all-purpose seasoning, ground cumin, salt (if using), and black pepper. Whisk vigorously until the eggs are well-beaten and uniform in color.
Combine and Bake: Pour the seasoned egg mixture evenly over the layered ingredients in the dish. Use a fork to gently stir and distribute the cheese and vegetable mixture throughout the eggs.
Bake: Place the dish into the preheated oven. Bake for 30 to 35 minutes, or until the center is fully set (a knife inserted should come out clean) and the top is lightly golden brown.
Rest and Garnish: Let the casserole rest for 5 minutes before slicing. If desired, garnish with chopped fresh cilantro before serving. Serve warm with your favorite toppings like salsa, sour cream, or guacamole.
