Preheat your oven to 375°F (190°C). Chop the zucchini, bell peppers, and onion into roughly 1-inch pieces. Toss the peppers with a little oil and roast on a baking sheet for about 15-20 minutes until slightly charred and fragrant.
While the vegetables roast, heat a large skillet over medium heat. Add a splash of oil, then sauté the diced onion and minced garlic until translucent and fragrant, about 5 minutes. Add the corn to warm through, stirring gently.
Once the vegetables are roasted and slightly caramelized, remove them from the oven. In a mixing bowl, combine the enchilada sauce with chopped cilantro and a squeeze of lime if you like. Stir well to blend the flavors.
Spread a thin layer of the sauce mixture on the bottom of your baking dish. Tear the tortillas into manageable pieces and layer half of them over the sauce.
Spread half of the roasted vegetables over the torn tortillas, then pour a third of the sauce over the top and sprinkle with a handful of shredded cheese.
Repeat the layering: add another layer of torn tortillas, followed by the remaining vegetables, sauce, and cheese. Finish with a final layer of tortillas and a generous sprinkle of cheese on top.
Bake uncovered for 20-25 minutes, until the cheese is bubbling and golden, and the sauce is thickened around the edges. If the cheese browns too quickly, tent the dish with foil to prevent burning.
Remove from the oven and let it rest for about 10 minutes; this helps the layers set for easier slicing. Garnish with extra cilantro if desired, then serve hot with lime wedges for a fresh finish.
