Prepare the grill for direct cooking over low heat (120° to 180°C).
In a small skillet over medium heat on the stove, crumble the chorizo and sauté until it is cooked through, 4 to 6 minutes, breaking it apart with a wooden spoon as much as possible. Transfer the chorizo to a paper towel to drain and cool for 5 minutes. Crumble it into small bits if necessary.
Lightly brush one side of each tortilla with oil. Place the tortillas, oiled side down, on a work surface. Assemble the quesadillas by spreading 3 tablespoons of the jalapeño cheese on one half of each tortilla. Top the cheese with equal amounts of chorizo, scallions, and another 3 tablespoons jalapeño cheese. Season evenly with the pepper. Fold the empty side of the tortillas over the filling.
Brush the cooking grates clean. Grill the quesadillas over direct low heat, with the lid closed, until golden on both sides, 4 to 6 minutes, turning once. Remove from the grill and let rest for about 1 minute. Cut the quesadillas into wedges and serve warm with guacamole, salsa, queso fresco, and cilantro.
Brush the cooking grates clean. Grill the quesadillas over low heat, with the lid closed, until golden on both sides, 4 to 6 minutes, turning once. Remove from the grill and let rest for about 1 minute. Cut the quesadillas into wedges and serve warm with guacamole, salsa, queso fresco, and cilantro.