Put flour, salt, and sugar in bowl of a food processor, and pulse to combine.
Add butter, and process for about 10 seconds, or just until the mixture resembles coarse meal.
Add ice water, tablespoon by tablespoon (1/4 to 1/2 cup), through the feed tube with machine running, just until the dough holds together without being wet or sticky; do not process more than 30 seconds.
Test the dough at this point by squeezing a small amount together. If it is crumbly, add a bit more water.
Wrap the dough in plastic wrap, using a rolling pin to flatten into a disk.
Chill until needed.