If you’ve ever savored the glorious, cheesy, lightly spicy bite of a traditional chile relleno but been intimidated by the process of roasting, peeling, and meticulously frying individual peppers, this recipe is your liberation. Welcome to the Baked Beef Chiles Rellenos Casserole, a dish that captures the soul-warming essence of the classic Mexican preparation but reimagines it as a simple, layered, family-style bake. It’s the ultimate comfort food hack—delivering all the complex, satisfying flavors with a fraction of the effort. Imagine layers of roasted poblano peppers, a savory and spiced ground beef filling, melty cheese, and a fluffy, custard-like batter that bakes into a golden, puffed masterpiece. This is not just a recipe; it’s a solution for busy weeknights, a showstopper for potlucks, and a guaranteed way to bring everyone to the table.

The beauty of this casserole lies in its deconstructed approach. We take the core components—the chiles, the filling, the binding egg mixture—and layer them strategically in a baking dish. The oven does all the heavy lifting, transforming the separate elements into a cohesive, bubbling, aromatic dish that is somehow both elegant and deeply comforting. The roasted poblanos provide a subtle, earthy heat that is the perfect backdrop for the richly seasoned beef. The cheeses—a combination of gooey Monterey Jack and sharp cheddar—create pockets of molten delight in every spoonful. And the simple egg and flour topping, reminiscent of a savory soufflé, puffs up around the edges, creating a beautiful texture contrast to the hearty layers beneath. It’s a complete meal in one dish, a celebration of flavor that feels special enough for company but is straightforward enough for a regular Tuesday.

The Cultural Context & A Modern Twist

Chiles Rellenos, which translates to “stuffed chiles,” is a classic dish with deep roots in Mexican cuisine, particularly beloved in the Puebla region. The traditional method involves stuffing fresh poblano chiles (after a careful roasting and peeling process) with cheese or picadillo (a minced meat mixture), dipping them in an airy egg batter, and frying them until golden. The result is sublime, but it’s a labor of love best suited for leisurely cooking sessions.

This casserole version is a testament to the beautiful evolution of home cooking. It respects the original flavors while adapting the technique for modern life. It’s part of a wonderful tradition of casserole cooking, where ingredients are combined and baked to perfection, making them ideal for feeding a crowd, meal prepping, or simply making dinner a less stressful affair. By baking everything together, the flavors have time to meld and intensify, creating a depth that is uniquely its own. It’s a dish that honors its origins while confidently carving out its own place in your recipe repertoire.

Gathering Your Ingredients

The ingredient list for this casserole is humble and accessible, yet each component plays a crucial role in building the final flavor profile. Let’s break it down.

For the Beef & Pepper Layer:

6-8 large fresh poblano peppers
1 tablespoon olive oil
1 pound lean ground beef (85/15 or 90/10 works well)
1 medium yellow onion, finely diced
3 cloves garlic, minced
1 teaspoon ground cumin
1 teaspoon dried oregano (preferably Mexican oregano)
1/2 teaspoon smoked paprika
1/4 teaspoon ground cinnamon (trust me, it adds a wonderful warmth)
1 (14.5 oz) can diced tomatoes, undrained
1 (8 oz) can tomato sauce
Salt and freshly ground black pepper, to taste

For the Cheese & Custard Layers:

2 cups shredded Monterey Jack cheese
1 1/2 cups shredded sharp cheddar cheese
4 large eggs
1 1/2 cups whole milk
1/2 cup all-purpose flour
1/2 teaspoon baking powder
1/2 teaspoon salt

For Garnish:

1/4 cup chopped fresh cilantro
1/4 cup Mexican crema or sour cream
1 lime, cut into wedges

Step-by-Step Instructions

This process is straightforward, but a few key techniques will ensure the best results. Read through the instructions once before you begin.

Roast the Poblano Peppers: First, preheat your oven’s broiler to high. Line a baking sheet with aluminum foil. Place the whole poblano peppers on the sheet and broil for 5-7 minutes per side, using tongs to turn them, until the skins are blackened and blistered all over. Immediately transfer the charred peppers to a heat-proof bowl and cover it tightly with plastic wrap. Let them steam for 15-20 minutes—this process loosens the skin, making them easy to peel. Once cool enough to handle, rub off the charred skin, then make a lengthwise slit in each pepper. Carefully remove the seeds and veins. Don’t worry if they tear a little; they will be layered in the casserole. Set them aside.
Prepare the Beef Filling: While the peppers steam, heat the olive oil in a large skillet over medium-high heat. Add the ground beef and onion and cook, breaking up the meat with a spoon, until the beef is browned and the onion is softened, about 8-10 minutes. Add the minced garlic, cumin, oregano, smoked paprika, and cinnamon. Cook for one more minute until fragrant. Drain off any excess grease.
Simmer the Sauce: Stir in the diced tomatoes with their juices and the tomato sauce into the beef mixture. Bring to a simmer, then reduce the heat to low and let it cook for about 10-15 minutes, allowing the flavors to meld and the mixture to thicken slightly. Season generously with salt and pepper. Remove from heat.
Preheat and Prep the Dish: Preheat your oven to 375°F (175°C). Grease a 9×13 inch baking dish with butter or cooking spray.
Assemble the Casserole Layers: This is where the magic starts. Arrange half of the roasted, peeled poblano peppers in a single layer on the bottom of the prepared baking dish. They can overlap slightly. Spoon the entire beef and tomato mixture over the peppers, spreading it into an even layer. In a medium bowl, toss the shredded Monterey Jack and cheddar cheeses together. Sprinkle about two-thirds of this cheese blend evenly over the beef layer. Now, arrange the remaining roasted poblano peppers over the cheese.
Create the Custard Topping: In a blender (or a large bowl using a whisk), combine the eggs, milk, flour, baking powder, and salt. Blend or whisk until the mixture is completely smooth and no lumps of flour remain. This batter is what will create that classic chiles rellenos “crust” as it bakes.
The Final Layer and Bake: Slowly and carefully pour the custard mixture over the entire casserole, trying to cover the top evenly. It will seep down into the layers, which is perfect. Top with the remaining cheese blend.
Bake to Perfection: Place the casserole in the preheated oven and bake for 45-55 minutes. The casserole is done when the top is puffed, deeply golden brown, and the center is set (a knife inserted near the center should come out clean). Let it rest for 10-15 minutes before serving. This rest time is crucial as it allows the layers to set, making it easier to slice and serve.

Pro Tips for a Flawless Casserole

Handling Hot Peppers: Wear disposable gloves when handling the roasted poblanos, especially if you have sensitive skin. The capsaicin oils can linger and cause discomfort.
Spice Level Control: Poblano peppers are generally mild, but occasionally you can get a spicy one. For an even milder dish, be thorough in removing all the seeds and inner white membranes. For more heat, add a finely minced jalapeño to the beef filling.
Make-Ahead Marvel: This casserole is a fantastic make-ahead meal. You can assemble the entire casserole (through step 7), cover it tightly, and refrigerate it for up to 24 hours. When ready to bake, you may need to add 5-10 minutes to the baking time since it will be going into the oven cold.
The Blender is Key: Using a blender for the custard topping guarantees a perfectly smooth, lump-free batter that will puff up beautifully. A few pulses is all it takes.
Don’t Skip the Rest: Resisting the urge to cut into the casserole immediately is hard, but that 10-minute rest allows the egg-based topping to firm up, ensuring you get clean, beautiful slices rather than a soupy mess.

Delicious Variations to Try

The basic framework of this casserole is wonderfully adaptable.

Cheese Lover’s: Swap the beef for a mixture of roasted corn, black beans, and sautéed mushrooms for a fantastic vegetarian version.
Chicken Version: Substitute the ground beef with 2-3 cups of shredded cooked chicken (rotisserie chicken works perfectly). Add it to the skillet with the spices and tomatoes.
Green Chile Twist: For a different flavor profile, you can substitute 2 (4 oz) cans of diced green chiles for half of the poblanos. There’s no need to roast the canned chiles.
Spicy Kick: Stir a 4 oz can of diced green chiles (like Old El Paso) into the beef mixture for an extra layer of flavor and a bit more heat.

Serving Suggestions

This casserole is a hearty main event, but a few simple sides can turn it into a feast.

Classic Sides: Serve with a scoop of warm Mexican rice and creamy, slow-cooked refried beans.
For a Lighter Meal: A simple, crisp green salad with a lime vinaigrette provides a refreshing contrast to the rich casserole.
The Toppings Bar: Set out small bowls of garnishes like chopped cilantro, diced red onion, sliced radishes, a drizzle of crema or sour cream, and plenty of lime wedges. Let everyone customize their own plate.
Perfect for a Crowd: This recipe easily serves 6-8 people and is a guaranteed hit at potlucks, holiday gatherings, or game day parties.

This Baked Beef Chiles Rellenos Casserole is more than just a meal; it’s a warm, cheesy, deeply satisfying experience that simplifies a classic without compromising on soul. It’s the kind of dish that creates memories around the dinner table, one delicious, comforting spoonful at a time.