Mexican Breakfast Casserole

Spice up your mornings with this Make-Ahead Mexican Breakfast Casserole, a Tex-Mex delight. Packed with layers of seasoned sausage, corn tortillas, Monterey Jack cheese, and zesty Hatch green chiles, this overnight casserole is perfect for holiday gatherings or cozy weekends. Prepare it the night before, pop it in the oven, and enjoy a stress-free, flavorful breakfast that brings the bold flavors of New Mexico and Texas to your table!

We totally love a great Make Ahead breakfast casserole and since we also love Tex Mex recipes we decided to bring those two loves together in this Tex Mex Breakfast Casserole.    This overnight Mexican breakfast casserole has layers of seasoned breakfast sausage, tortillas, Monterey Jack cheese, and green chile. This is a make Ahead Mexican Breakfast Casserole with tortillas and is a spin-off of a Tex Mex Breakfast Casserole idea. 

It’s topped with cheese and sliced jalapeños to make one of the best Mexican Breakfast Casseroles we have ever tried.   We are bringing our love of New Mexico and Texas together with this dish.   If it is too spicy then the jalapeños can be left off.

During the holidays or when we have company here at the Ranch, it’s always nice to throw together a breakfast casserole the night before.   It makes the mornings so much nicer to be able to sit on the front porch and watch the sunrise as breakfast is cooking.    We are able to enjoy our guest so much more when our morning starts off with this delicious casserole but we didn’t have to spend much time in the kitchen.

1. Prep your baking dish: Lightly spray a 9×13-inch baking pan with nonstick cooking spray and set it aside. This keeps everything from sticking and makes cleanup a breeze.
2. Cook the sausage mixture: In a large skillet over medium heat, cook the sausage and diced onions together until the sausage is nicely browned and the onions are soft and translucent. Stir in the chili powder, mixing well to distribute the flavor, then remove the skillet from the heat. (Drain any excess grease if needed for a lighter version.)
3. Layer the casserole: Start building those delicious layers in your prepared pan:

• Spread ½ cup of the green chile sauce (or 505 Southwestern Green Chile) evenly over the bottom.
• Sprinkle on one-third of the sausage-onion mixture.
• Arrange half of the cut corn tortilla pieces over the sausage.
• Sprinkle with 1 cup of shredded Monterey Jack cheese. Repeat the layers once more: another ½ cup green chile (if using more), another third of the sausage mixture, the remaining tortilla pieces, and another 1 cup of cheese.

1. Finish the top layer: Add the final third of the sausage mixture, the remaining ½ cup of green chile sauce, and finish with the last 1 cup of shredded cheese on top. Your casserole should be beautifully layered and ready for the egg mixture.
2. Make the egg custard: In a large bowl, whisk together the eggs, milk, salt, and black pepper until well combined and slightly frothy. Gently and evenly pour this mixture over the entire casserole, making sure it soaks down into all the layers.
3. Refrigerate overnight: Cover the pan tightly with plastic wrap or foil and refrigerate for at least 6 hours, or preferably overnight. This make-ahead step lets all the flavors meld beautifully and gives you a stress-free morning.
4. Bake the casserole: When ready to bake, remove the casserole from the refrigerator and let it sit on the counter for about 1 hour to come to room temperature. Preheat your oven to 350°F. Bake uncovered for the first 50 minutes, then cover loosely with foil for the last 30 minutes (total baking time about 80 minutes) to prevent the top from over-browning. The casserole is done when the eggs are set and the center is hot.
5. Rest and serve: Remove from the oven and let it stand for 10 minutes before slicing. This helps it hold together nicely for clean portions.

Serving suggestions: Top with fresh salsa, diced avocado, chopped cilantro, or a dollop of sour cream. It pairs wonderfully with mimosas, fresh fruit, or a simple green salad for brunch. Leftovers reheat beautifully too!

This hearty Tex-Mex casserole is perfect for busy ranch mornings, holiday gatherings, or feeding a crowd. Simple, flavorful, and make-ahead friendly—just the way we like it on the ranch! 🌶️

This Make-Ahead Mexican Breakfast Casserole is a game-changer for busy mornings or festive gatherings, blending bold Tex-Mex flavors with the convenience of overnight prep. Whether you’re serving it for breakfast, brunch, or even dinner, its layers of sausage, green chiles, and cheesy goodness are sure to impress. Try this crowd-pleaser and save the recipe for a deliciously spicy start to your day!

This Mexican Breakfast Casserole is absolutely delicious and great for company.   But we don’t wait for company to arrive to enjoy those south of the Border flavors.   This is great reheated the next day and we have even had it for dinner.

Note: We normally serve this with our Homemade Roasted Jalapeño Salsa and even a Mimosa for special occasions. 

 🥣 Recipe