Preheat oven to 350°F. Line cookie sheet. Toast pecans without burning them. Beat butter and sugar until creamy. Add vanilla, then beat eggs one at a time. In separate bowl, whisk flours, starch, baking powder and salt; then add to the batter without over-mixing. Chop the chocolate chips and pecans, then stir into batter. Place dough in center of large piece of plastic wrap. Form a flat log about the length of your cookie sheet. Flip onto cookie sheet and remove wrap. Brush with beaten egg white and sprinkle top with sugar. Bake 30min. until golden. Remove from oven and set to 275°F. Let cool 2minutes, then slice at an angle every 1/2 inch to form 12 biscotti. Place 1/2 inch apart, upside-up, on cookie sheet. Bake 25min.