Heston took on an Italian favourite - risotto. He visited Gualtieri Marchesi in Lombardy, Italy, whose saffron risotto with gold leaf has earned him three Michelin stars. Then, having paid respects to the old guard, he visited a new-wave Italian chef, Carlo Cracco, who flavours his risottos with some extraordinary ingredients, including instant coffee and anchovies. Heston visited two of Italy's top rice producers, before returning home to decide on what he was going to do with this most simple of dishes - it turns out to be one of his biggest challenges.

• Heston Blumenthal