Sift together the flour and salt into a mixing bowl.
Cut the margarine into pieces with a knife, add to the flour and rub in with your fingertips.
Add the grated cheese, parsley and pepper. Ask an adult to help you break the egg into a cup and beat with a fork. Add enough of the beaten egg to make the dough stiff.
Wrap the dough in greaseproof paper and put in the refrigerator for 15 minutes.
Lightly flour a clean work surface. Then using a rolling pin; roll the dough into a rectangle about 1 cm thick. Cut into strips about 7.5 x 2 cm.
Carefully transfer them on to a baking sheet. Put in the oven and bake for 15 minutes. (Always ask an adult for help at this stage)