Preheat the oven to 350°F (175°C). Grease a 9x13 inch baking dish.

In a mixing bowl, whisk together the eggs, milk, flour, baking powder, and salt until smooth.

Spread the diced green chilies and cooked meat (if using) evenly in the bottom of the greased baking dish.

Pour the egg mixture over the chilies and meat.

Sprinkle the shredded cheese evenly on top.

Bake in the preheated oven for 45 minutes, or until the casserole is set and golden brown on top.

Let cool for a few minutes before slicing and serving.