Preheat oven to 400°. In a small bowl, combine the first 8 ingredients; fold in crab.
In a small skillet, cook pancetta over medium heat until partially cooked but not crisp; drain on paper towels.
Unfold 1 sheet of puff pastry. Spread half the crab mixture to within ½ in. of edges. Sprinkle with half the pancetta and half the cheese.
Roll up the left and right sides toward the center, jelly-roll style, until rolls meet in the middle. Repeat with remaining pastry and ingredients.
Refrigerate until firm enough to slice, about 30 minutes.
Cut each roll crosswise into ½-in. slices. Place 2 in. apart on parchment-lined baking sheets.
Bake until golden and crisp, 15-20 minutes. Cool on pans 2 minutes. Remove to wire racks to cool.
