1. Heat 2 tablespoons olive oil in a large nonstick skillet. Add green pepper, mushrooms, salt and black pepper. Saute over medium-high heat for 5 minutes or until pepper softens, stirring occasionally. Remove from heat.
2. Place four tortillas on a flat work surface. Place about 1/3 cup pepper-and-mushroom mixture over each, dividing evenly. Sprinkle 1/3 cup cheese over each tortilla. Top each with another tortilla.
3. Wipe out skillet. Coat with nonstick cooking spray and heat over medium-high heat. Place 1 quesadilla in the skillet and cook 2 minutes, gently pressing down with a spatula. Turn and cook an additional 1 to 2 minutes, until quesadilla is lightly browned and cheese melts. Remove from skillet and keep warm. Repeat with remaining quesadillas.
4. To serve, heat corn. Cut each quesadilla into wedges and serve with the corn. Makes 4 servings.