Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13 inch baking pan.
In a medium bowl; mix together shortening, white sugar, 1/2 cup brown sugar, and egg yolks. Stir in water and vanilla. In a separate bowl, sift together flour, baking soda, and salt. Combine with egg and sugar mixture; blend well. Stir in chocolate chips. Press into the bottom of the prepared pan.
In a large glass or metal mixing bowl, beat egg whites until soft peaks form. Gradually add 1 cup brown sugar, continuing to beat until whites form stiff peaks. Spread meringue on top of base, covering completely.
Bake in preheated oven until meringue has risen and light brown in color, about 15 to 20 minutes. Leave to cool before cutting into bars.