Gregg Wallace is in the Netherlands at one of the world's biggest sauce factories. Its annual output is a quarter of a million tonnes of condiments,and more than 50 per cent of this heads to the UK. Meanwhile Cherry Healey is making the glass jars Gregg needs for his mayonnaise. She's at a vast factory in Maastricht where a furnace holding 250 tonnes of molten glass has been running continuously for the last 11 years.