Optional toppings: Sour cream, salsa, guacamole, or fresh cilantro
Prepare and Cook the Shrimp:Pat the shrimp dry and chop them into bite-sized pieces if desired (or leave whole for bigger bites). In a bowl, toss the shrimp with olive oil, minced garlic, cumin, chili powder, lime juice, salt, and pepper. Let them marinate for 5 minutes while you prep the veggies.
Heat a large skillet over medium-high heat. Add the shrimp mixture and cook for 2-3 minutes, stirring occasionally, until the shrimp are pink and opaque. If using onion and bell pepper, add them to the skillet halfway through and sauté until softened. Remove from heat and set aside.
Assemble the Quesadillas:Wipe out the skillet and return it to medium heat.Lay one tortilla flat. Sprinkle a thin layer of cheese (about 1/4 cup) over half of the tortilla.Spoon a quarter of the cooked shrimp mixture over the cheese.Top with another 1/4 cup of cheese (this helps everything stick together).Fold the tortilla over to create a half-moon shape. Cook to Perfection:Add a small pat of butter or a drizzle of oil to the skillet. Place the folded quesadilla in the pan and cook for 2-3 minutes per side, pressing down gently with a spatula, until the tortilla is golden and crispy and the cheese is melted. Repeat with the remaining tortillas and filling.
Serve:Let each quesadilla rest for 1 minute on a cutting board, then slice into wedges. Serve hot with your favorite toppings like sour cream, salsa, or guacamole.