Green Chile Egg Casserole is our family's favorite easy overnight breakfast casserole recipe with a southwest flavor. It's super easy, mild in flavor and can be made the night before to make your morning a breeze.

Lots of folks have their own versions of this recipe, but I have a special method that makes this recipe the best.

Slice of green chili egg casserole on a grey dish with a fork next to glasses of orange juice and a white napkin in a breakfast scene — Ready for breakfast with this fabulous egg casserole!

Overnight Egg Casserole

We make this savor breakfast recipe for Christmas, Easter, Mother's Day brunch, and any other time that calls for a big fabulous breakfast. But, just because it's served on holidays doesn't mean it's complicated. It's an overnight breakfast casserole, too!

Egg casseroles are great for make-ahead meals. You can prepare the dish, combining all of the ingredients into the baking dish, and then cover it and refrigerate for up to two days. When you're ready to eat the casserole, just remove it from the fridge, preheat the oven and bake.

What kind of chiles go into Green Chile Egg Casserole?

One of the things that makes this recipe special is the Southwest flavor from the diced green chiles. If you're not a fan of heat, never fear. Just make sure the can of diced green chiles you grab is labeled 'mild'.

These kind of chiles are made from the mild New Mexican peppers like the Anaheim. They're just as mild as bell peppers and add a ton of flavor.

You can find mild diced green chiles in most supermarkets in the US near the salsas.

the ingredients to make green chili egg casserole - an easy overnight breakfast casserole - eggs, green chilis, flour, baking powder, butter, cottage cheese, colby jack or cheddar cheese

Why is this version of Green Chile Egg Casserole Unique?

There are tons of versions of this recipe but I have perfected it in the decades since I first received it.

The secret? I keep it simple.

Lots of the recipes out there will suggest beating the eggs separately or mixing things in different steps. Sure you can do that, but I prefer to dump everything into a bowl and mix it together all at once. Call me lazy, but the end product is delicious.

The ingredient ratios are perfect so that it combines nicely and it results in a nice, tender, melt in your mouth bite. I've experimented with different ratios of cheese, chilies, eggs, butter, flour, and this has been the final outcome after years of making this dish.

a large bowl mixing together the ingredients: eggs, cottage cheese, chilis, flour, baking powder and shredded cheese — Mix together all the ingredients in one bowl

Don't skip the butter!

The other secret and the step you don't want to skip is the butter! I melt ¼ cup of butter and drizzle half of it into the baking pan before adding the egg mixture. Then I drizzle the remaining over the top of the egg mixture before popping it into the oven.

The butter interacts with the protein in the eggs and cheese to create a thin, crispy crust on the bottom and top. See those golden browned edges and top? They're making this crust-less quiche completely crave-worthy.

A pan prepared with melted butter ready to make the overnight egg casserole — Prepare a 9 x 13 baking dish with a drizzle of melted butter in the bottom

second step in the prep process of making egg casserole is to pour in the prepared ingredients and then top with more melted butter — Pour the mix into the prepared 9 x 13 pan and drizzle with more melted butter

A pan fresh out of the oven filled with easy overnight breakfast egg casserole with green chilis - viewed on a close up angle — fresh out of the oven - golden and slightly browned

Make it Keto or Gluten-Free

This breakfast casserole is easy to make keto by skipping the flour and baking powder. The final texture will be a bit firmer, but it will still be super tasty.

You can make it gluten free by substituting your favorite all-purpose flour replacement, like Bob's Red Mill 1 to 1, for the regular all purpose flour.

Tips for Making Green Chili Egg Casserole

Not a fan of cottage cheese? Lot's of people aren't but I promise the final dish doesn't resemble cottage cheese. The curds melt in with the rest of the ingredients and give this savory casserole its tasty texture. Even self-proclaimed cottage cheese haters like this recipe.
Grate your own shredded cheese. Pre-shredded cheeses are treated with potato starch to prevent clumping in the package. It's completely harmless and flavorless, but it does impact the magical melty quality of cheese. It's worth the extra five minute to grate your own.
Get creative! This egg casserole can be jazzed up by adding in cooked diced bacon, diced scallions, or diced jalapenos if you like it spicy.
You can also substitute different cheeses if you'd like. Any variety of cheddar will work great or even mozzarella for something more subtle. You can also do combinations of different cheeses. Make it a four cheese egg casserole if you're feeling creative.

Slice of green chili egg casserole on a grey dish with a fork next to glasses of orange juice

Reheating Egg Casserole

This recipe makes enough for a crowd. When I make it for my family of four, we always have leftovers. Good news, it tastes just as great the next day.

The best way to reheat any casserole is to bake it at a low temperature in the oven covered with foil for 20 - 30 minutes. This will ensure that it won't dry out and will get it nice and piping hot.

This casserole also freezes well. I like to cut it into single servings into an airtight container or bag and freeze for up to 4 months. When I'm ready to eat them again, I remove one from the freezer, place it on a microwave safe plate and cover it with a paper towel, and microwave for 1 minute on defrost or 50% power. Then I microwave it for another minute at full power and it should be heated and ready to eat.