Saturday Kitchen's James Martin wants to convince us to cook with different sorts of eggs, rather than always choosing the tried and trusted hen option. He travels to meet duck and quail egg producers who are trying to revive the fortunes of these once popular eggs. Among the dishes he creates in the Revival kitchen is a magnificent sponge cake made with duck eggs which looks nothing less than spectacular.Irish-born chef Richard Corrigan is a keen fisherman and is passionate about fresh fish but he is shocked to discover that we export the vast majority of our mackerel catch. He is determined to change our attitudes to this rather overlooked fish by proving that not only is it incredibly good for us but that it tastes delicious too. He devises a range of wonderful recipes which showcase the benefits of cooking with locally caught fresh mackerel.