Preheat oven to 300 degrees. Place the pecans on a rimmed baking sheet and bake until fragrant, 3 to 5 minutes. Let cool. Transfer the pecans to the bowl of a food processor and pulse until finely ground.
Add the flour to the ground pecans, pulse briefly to combine. Add butter and pulse until mixture resembles coarse meal. Add the cheese and process until the dough comes together and is well combined.
Transfer dough to a clean work surface. Shape the dough into a 2 1/2-inch-wide log. Wrap the log with plastic wrap and refrigerate for at least 24 hours.
Preheat oven to 325 degrees. Slice the well-chilled log into 1/4-inch-thick slices. Transfer slices to a baking sheet and bake immediately, rotating the sheet halfway through cooking, until the crackers are golden brown and firm in the center, 25 to 35 minutes. (The crackers should not get too dark around the edges.) Transfer to a wire rack to cool. The crackers may be made a day ahead and kept in an airtight container at room temperature.