Cook the peppers in the oven.
Heat the oven’s broiler and place the rack about 6 inches below the heat.
Cover a baking tray with aluminum foil and put the peppers on top.
Cook for 10-15 minutes, turning occasionally with tongs, until the skins are dark and burnt.
Put the grilled peppers in a plastic bag and let them sit for 10 minutes to steam and cool down.
After they cool down, peel the skin off, cut the stems, open them, and take out the seeds.
Heat the oven before using.
Heat the oven to 350°F (175°C) before using.
Spray a 3-quart baking dish with nonstick spray.
Make the casserole.
Place half of the cooked chilies in the baking dish in one layer.
Put 1 cup of Monterey Jack cheese and 1/2 cup of cheddar cheese on top.
Repeat the process with the rest of the chilies and cheese.
Make the Egg Mix: In a bowl, mix the eggs, milk, flour, baking powder, onion powder, garlic powder, salt, and black pepper until smooth and without any lumps.
Pour the mixture evenly on top of the cheese and peppers.
Cook in the oven for 45 minutes until the middle rises and the eggs are firm and golden on the sides.
Allow the dish to cool for 5-10 minutes before slicing it.
To serve: Cut into squares and add a spoonful of sour cream, salsa, and freshly chopped cilantro. Have fun!