Marble Fudge Cookies

In a large bowl, mix flour, shortening, sugar and baking soda with a mixer. Add the egg and colored chips. Mix until dough forms. On a floured board, roll the dough into a log, about the size of a salami or 2 1/2" in diameter.
Preheat oven to 350 degrees, Spray cookie sheet with cooking oil spray. Slice log into 1" thick slices each and place on cookie sheet. Bake for 15-20 minutes.