Shrimp Quesadillas with Grill-Your-Own Salsa

Prepare a charcoal fire or heat a gas grill to medium-high, and oil the grates. Brush the tomato halves (cut and skin sides), onion slices, and jalapeño with canola oil. Thread the shrimp onto skewers, brush them with canola oil, and sprinkle on seafood seasoning. Grill the vegetables for 3 to 4 minutes per side or until they have blistered, then transfer them to a clean dish. Grill the shrimp until they have turned opaque and are firm to the touch, about 2 to 3 minutes per side. Remove the shrimp from the skewers. Place 2 tortillas on the grill and quickly top half of each with a quarter of the shrimp and a quarter of the cheese. Fold the torillas in half and grill them until you have visible grill marks, flipping them once, about 2 minutes per side. Stack the quesadillas on top of one another so they will stay warm while you grill the second batch. Bring everything inside. Peel the tomatoes, and remove the seeds and white membrane from the jalapeño (parents only). Then chop all the vegetables and transfer them to a serving bowl. Stir in the cilantro, salt, and lime juice. Cut the quesadillas into wedges and serve them with the salsa, sour cream, and fresh sprigs of cilantro. Serves 4.