Step 1: Cook the Vegetables : Heat olive oil in a skillet over medium heat. Add onions and cook until softened. Add bell peppers, zucchini, and mushrooms. Season with salt, pepper, cumin, paprika, and garlic powder. Cook for 5–7 minutes until the veggies are tender and slightly browned. Remove from heat and set aside.
Step 2: Make the Guacamole ; Cut avocados in half, remove the pit, and scoop the flesh into a bowl. Mash lightly using a fork. Add chopped tomato, onion, cilantro, and lime juice. Season with salt. Mix gently and set aside.
Step 3: Assemble the Quesadillas : Place a tortilla in a clean skillet over medium heat. Sprinkle a generous layer of cheese on half of the tortilla. Add a spoonful of the cooked vegetables. Add another light layer of cheese on top (to help seal). Fold the tortilla in half.
Step 4: Cook the Quesadillas :Cook for 2–3 minutes on each side until golden brown and crispy. Transfer to a cutting board and repeat with remaining tortillas. Slice each quesadilla into triangles.
Step 5: Serve : Serve warm, with guacamole on the side for dipping or spreading.