If using the food processor: Finely chop herbs in the food processor bowl and add all remaining ingredients, then process using pulse button, until mixture turns into a crumble.
As soon as this happens, stop processing and turn out the mixture into a bowl. Gather into a dough. Chill for 30 minutes before using.
If making the dough by hand: chop the herbs using a knife on a board. Put all remaining ingredients except the egg and butter into a large bowl. Rub in the butter or margarine until crumbly. Add beaten egg and bind together into a dough (using a fork). Chill for 30 minutes before using.