In a large mixing bowl, cream margarine and sugars. Add in egg, one at a time, beating after every addition. Mix in vanilla.
In a separate bowl, combine oats, flour, baking soda, and salt. Mix together then slowly add into the margarine mixture. Add about a cup at a time, mix, then add another cup. Do this until it is all blended together. Mix in chocolate chips.
Form dough into medium size balls, place on cookie sheet covered with a silpat, and bake for about 10 minutes.