Preheat oven to 375 F. Line two baking sheets with parchment paper, set aside.
Drain crab meat, place in a mixing bowl. PIck through and remove any bits of shell, if present.
Add all filling ingredients - except crab and salt/pepper- to a food processor. Blitz until everything is chopped up, well combined, and smooth.
Add cheese mixture to the bowl of crab, mix to combine. Season with salt and pepper, to taste.
Carefully separate 2 sheets of phyllo dough from the rest. This can be an infuriating process. Cover the remaining phyllo dough.
Lay one sheet out flat on a work surface, lightly brush it with melted butter.
Top it with the other sheet, then cut it into 5 equal widths (the shorter side of the long sheet becomes the length of the strips).
Spoon a tablespoon or so of filling onto one end of a strip, then fold it up: fold the short edge to match up with the side (covering the filling), the fold that over so it matches up with the same side, etc - flag style.
Repeat with remaining strips, then make a new set of strips. Continue till you run out of either dough or filling - which depends on how many sheets you destroyed in the process, and how generously you filled the triangles.
Arrange triangles on a lightly greased baking sheet, and brush the tops with melted butter.
Bake for 20 minutes, or until golden and flaky.