Overview: Test cook Becky Hays makes savory Mushroom Bourguignon. Tasting expert Jack Bishop challenges hosts Bridget Lancaster and Julia Collin Davison to a head-to-head tasting of Veggie Burgers. Science expert Dan Souza uses a soda can and some science to explain cooking with aluminum. Test cook Lan Lam cooks main course-worthy White Bean and Mushroom Gratin.