Preheat oven to 350°F. Coat a 7-by-11-inch baking dish with cooking spray.
Heat 1 tablespoon oil in a large skillet over medium heat. Add ½ cup onion and ½ cup pepper; cook, stirring, until softened, about 3 minutes. Add minced garlic; cook until fragrant, 1 minute. Add chopped greens, rinsed beans, ½ cup corn and ⅛ teaspoon salt; cook, stirring, until the greens are wilted, about 2 minutes. Stir in ⅓ cup enchilada sauce and remove from heat.
Place 1 tortilla on a clean work surface. Place about 1 tablespoon cheese in the center of the tortilla. Top with about ¼ cup of the vegetable mixture; roll the tortilla over the filling. Place the filled tortilla, seam-side down, in the prepared baking dish. Repeat with the remaining tortillas. Spread the remaining ⅔ cup enchilada sauce over the tops of the rolled tortillas. Top with the remaining ½ cup cheese.
Bake until the cheese is melted and bubbly, about 20 minutes. Let stand for 5 minutes before serving. Garnish with cilantro and/or sour cream, if desired.
