If you are making the pimento cheese from scratch, make it first and measure out ¾ cup; otherwise have ¾ cup pimento cheese ready. Preheat the oven to 450°F (232°C). Line one or more rimmed baking sheets with parchment paper.
Spread the frozen waffle fries from the 120-ounce bag in a single layer on the prepared baking sheet(s). If they do not fit on one sheet, use additional sheets or bake in batches so the fries are not crowded.
Bake the fries 20 to 25 minutes, flipping once and rotating sheets halfway through if needed, until the fries are hot and crispy.
Remove the baking sheet(s) from the oven. Dollop the entire ¾ cup pimento cheese over the fries in evenly spaced spoonfuls.
Return the sheet(s) to the oven and bake 4 to 5 minutes, watching closely, until the pimento cheese is melted and beginning to ooze.
Remove from the oven, sprinkle 3 tablespoons chopped fresh chives over the melted cheese, and serve immediately with pickles.