I think its called either a Pastry cutter, Pastry wheel, Pasta cutter or Pasta wheel. May have the word "Fluted" in it also ( Fluted Pastry Cutter ..) Thats assuming Im thinking of the same thing you are describing : smile:
taxy, there is a cut of pasta called "silk handkerchief". They're large-ish squares of pasta, traditionally served with pesto. They made them on "The Chew" a few years ago, but they used a different sauce.
otuatail, I think larry nailed it. I've seen that called a "pastry wheel" also.