Heat oven to 350. Cream shortening with sugar. Mix in egg, sour cream, vanilla. Melt 1 1/2 cups chocolate chips and blend with creamed mixture. Stir flour with salt, baking powder, baking soda. Add dry ingredients to creamed mixture, stirring until smooth. Fold in nuts and remaining chocolate chips. Chill dough 1/2 hour. For giant cookies, use ice cream scoop or 1/4 cup dough for each cookie. Place on 3 greased baking sheets. Flatten slightly to 3 inches. Bake for 10 to 12 minutes or unti still slightly soft in the center. Makes 16 giant cookies.