Position a rack in the top shelf of the oven and preheat to broil. Arrange the corn chips on a large, heatproof platter in a single layer to overlap slightly. Sprinkle the cheese over the chips, then dot evenly with the salsa, pickled jalapenos and fresh jalapeno.
Broil until the cheese is bubbling, 3 minutes. Remove the platter from the oven, dollop with the sour cream and sprinkle with one-third each scallions and cilantro. Serve the remaining scallions and cilantro in small bowls alongside.