This vibrant tortilla casserole is generously packed with a colorful array of sautéed vegetables—including sweet onions, crisp red pepper, fresh corn, and tender zucchini—combined with hearty black beans, fragrant herbs, and gooey Monterey Jack cheese. The result is a super flavorful and deeply satisfying vegetarian dinner that’s perfect for any occasion.

While optional, preparing the homemade red enchilada sauce is highly recommended. It takes just 15 minutes to craft and introduces an unparalleled depth of smoky, spicy, and tangy flavors that truly elevate the casserole. This dish is designed for culinary creativity; feel free to improvise with ingredients you have on hand. Mushrooms, Swiss chard, kale, or even eggplant would all make excellent additions, allowing you to tailor this wholesome meal to your preferences and seasonal availability.

• 2 tablespoons olive oil
• 1 large onion, finely diced
• 2 bell peppers (any color), diced
• 1 large zucchini, diced into half-inch pieces
• 2 ears of fresh corn, shucked, kernels stripped (about 1.5 cups)
• 1.5 cups cooked black beans, rinsed and drained (see notes below)
• 2 cups homemade red enchilada sauce (or high-quality store-bought)
• 9 to 12 flour or corn tortillas (6-inch to 8-inch), depending on pan size (see notes below)
• 6 scallions, thinly sliced, divided for layers and garnish
• 1 large bunch fresh cilantro, finely chopped, divided for layers and garnish
• 8 ounces Monterey Jack cheese, freshly grated

Instructions

1. Prepare the Vegetables: In a large sauté pan or cast-iron skillet, heat the 2 tablespoons of olive oil over high heat until it shimmers. Immediately add the diced onions and bell peppers. Season with a generous pinch of salt. Reduce the heat to medium and sauté for 4 to 5 minutes, stirring frequently to prevent burning, until the vegetables are softened and slightly translucent. Add the diced zucchini, season with another pinch of salt, and continue to cook for 2 to 3 minutes more, just until the zucchini begins to tenderize but still retains a slight crispness. Finally, stir in the fresh corn kernels, season with a final pinch of salt, and cook for only about 1 minute to warm through. Remove the pan from the heat.
2. Combine with Beans: To the skillet with the sautéed vegetables, add the cooked black beans. Stir thoroughly to combine all the ingredients. Taste the mixture and adjust seasoning with salt, and if desired, a dash of your enchilada sauce for extra flavor, ensuring it’s perfectly seasoned.
3. Preheat Oven and Prep Pan: Preheat your oven to 425ºF (220ºC). Lightly grease a 9-by-13-inch baking dish (or a similar sized oven-safe dish like a 9-inch square or round casserole dish). Pour a thin, even layer of enchilada sauce (approximately 3/4 cup) onto the bottom of the prepared baking dish, spreading it to cover.
4. Begin Layering: Arrange a single layer of tortillas over the sauce, overlapping slightly if necessary, and trimming the edges to fit the contours of your dish. Scatter a handful of fresh cilantro and thinly sliced scallions evenly over the tortillas. Spoon about one-third of the vegetable-bean mixture over the herbs, spreading it gently. Sprinkle a generous layer of grated Monterey Jack cheese over the vegetable mixture. Spoon another thin layer of enchilada sauce over the cheese, using the back of a spoon to spread it evenly. Repeat this layering sequence: tortillas, herbs, vegetable-bean mixture, cheese, and sauce. Continue until you have built three (or four, if your pan allows) distinct layers of tortillas, ending with the vegetable-bean mixture and cheese.
5. Final Topping: For the top layer, spoon a final thin layer of enchilada sauce over the last layer of tortillas. Scatter the remaining fresh herbs (cilantro and scallions) generously over the sauce. Finally, add the last layer of grated Monterey Jack cheese, ensuring it covers the entire surface for a beautiful, golden crust.
6. Bake and Serve: Place the assembled casserole in the middle or top rack of your preheated oven. Bake for 15-25 minutes, or until the cheese topping is bubbly, melted, and golden brown in spots. Keep an eye on it to prevent over-browning. Once baked, remove the casserole from the oven and, if desired, garnish with more fresh cilantro and scallions for a vibrant finish. Critically, let the casserole rest for at least 10 minutes before cutting and serving. This allows the layers to set, making for cleaner slices and a more enjoyable eating experience. Serve warm and savor every delicious bite!

• Black Beans: For the freshest and most flavorful black beans, we highly recommend our preferred method for preparing them: Simplest Slow Cooker Black Beans. This recipe also includes instructions for using an Instant Pot for convenience, ensuring perfectly cooked beans every time. If using canned beans, make sure to rinse and drain them thoroughly before adding to the vegetable mixture.
• Tortillas: While we often prefer using soft flour tortillas for their pliability and texture, this casserole works wonderfully with corn tortillas as well if that’s your preference. For an artisanal touch, we adore Caramelo tortillas when available. If those are not an option, look for high-quality store-bought tortillas made from a blend of flour and corn, which often offer a great balance of flavor and texture (many brands at Trader Joe’s and Whole Foods offer excellent choices). For an extra special touch, you can even make your own flour tortillas from scratch, or try our unique sourdough version. Regardless of your choice, if using store-bought tortillas, it’s beneficial to lightly toast them on both sides in a dry skillet until they begin to soften and lightly brown; this enhances their flavor and prevents them from becoming soggy in the casserole.
• To Freeze for Later Enjoyment: This vegetarian tortilla casserole is an excellent candidate for meal prep! To freeze, assemble the casserole exactly as instructed, stopping just after you spoon the enchilada sauce over the final layer of tortillas (before adding the last layer of herbs and cheese). Cover the dish tightly with a few layers of aluminum foil to prevent freezer burn. It can be stored in the freezer for up to 3 months.
• To Thaw and Bake (from frozen): When you’re ready to enjoy, transfer the frozen casserole to the refrigerator to thaw overnight. Once thawed, preheat your oven to 375ºF (190ºC). Bake the covered casserole for 20 minutes. Then, remove the foil, sprinkle over a fresh layer of scallions, cilantro, and the final layer of grated cheese. Increase the oven temperature to 425ºF (220ºC) and continue to bake for about 15 minutes, or until the cheese is bubbly, golden, and beginning to blister. Let it rest for 10 minutes before serving.