In this episode, greengrocer cum MasterChef host Gregg Wallace makes a case for the revival of the humble spud. All too often replaced by rice or pasta on our plates, tasty tatties need more respect in Gregg's opinion. He tracks down some heritage varieties that are full of flavour, and whistles up three fabulous dishes including a definitive shepherd's pie and his own favourite, dauphinoise potatoes.Pinning her flag to the mast of rare breed pork is Clarissa Dickson Wright. Never one to mince her words, Clarissa believes that government meddling in the 1950s has left us with flavourless commercial pigs, with none of the character of our native breeds. She meets some of the hardworking farmers battling to preserve our rare breed porkers and lets us in on some of her cooking secrets, including how to get perfect crackling on your Sunday roast.