For flaky pie dough, the fat is cut or rubbed into the flour until the particles of shortening are about the size of peas or hazelnuts—that is, the flour is not completely blended with the fat, and the fat is left in pieces. (Many bakers distinguish between this crust, which they call short-flake, and long-flake crusts, in which the fat is left in pieces the size of walnuts and the flour is coated even less with shortening. Blitz puff paste, introduced in the next chapter, is actually a long-flake pie dough that is rolled and folded like puff paste.)
