In a large skillet, heat olive oil over medium heat. Add the diced red onion and garlic, and sauté for about 2-3 minutes until softened.
Add the diced red and green bell peppers, zucchini, and corn to the skillet. Season with cumin, smoked paprika, salt, and pepper. Cook for an additional 5-7 minutes until the vegetables are tender.
Stir in the black beans and cook for another 2 minutes, just to heat through. Remove the skillet from the heat once the mixture is done.
Lay one tortilla flat and sprinkle half of the shredded cheese on one half of the tortilla. Spoon a generous amount of the veggie mixture over the cheese, then top with the remaining cheese. Fold the tortilla in half.
In the same skillet, increase the heat to medium-high. Add the folded quesadilla and cook for 3-4 minutes on each side until golden brown and the cheese is melted. Repeat with the remaining tortillas.
Remove the quesadillas from the skillet and let them sit for a minute. Slice them into wedges.
Garnish with fresh cilantro, and serve with salsa and sour cream on the side.
Notes
Feel free to customize the veggies based on your preference.