Stefan's journey begins with the E number colours. Stefan discovers why these chemicals don't just affect the look of our food but its taste as well. He learns what the colour in some of our cakes and sweets has to do with insects and flamingos and why some of the E number colours could have side-effects.

Stefan also delves into the world of flavourings and reveals why eating monosodium glutamate could be no worse for you than eating cheese or mushrooms. He also gains rare access to the magical world of the flavourings industry which can transform your food beyond recognition. His final test sees him using E numbers to get vegetable-hating kids to eat their first brussel sprouts in years.