Heat 2 Tbl of the olive oil in a large sauté pan over high heat. Season the shrimp with the old bay seasoning. Place shrimp in the oil and cook 3 minutes. Add crushed red pepper, sliced mushrooms, diced onion and red bell pepper. Cook 6-7 minutes more. Add garlic, creole seasoning and black pepper. Cook for 2 minutes more. Remove from heat and stir in the green onions. Allow mixture to cool completely.
Once the quesadilla filling is cool, add the pesto and shredded cheese, blend well.
Lay the flour tortillas on a flat surface and divide the filling evenly among them. Spread filling to cover one half of the tortilla. Fold the tortilla in half to form a semicircle.
Prepare the grill. Using a pastry brush, lightly coat the two sides of the quesadilla with the remaining olive oil. Grill the quesadillas over direct medium heat until well marked, about 4-6 minutes on each side. Rotate the quesadillas while cooking to prevent burning.
Remove the quesadillas from the grill and cut them into 4-6 triangles.
Yield: 6-10 servings