Richard Johnson travels to Los Angeles, a city where many of the world's food trends begin. With the US economy in crisis LA's "food truck" scene is growing. People who have lost jobs are finding new careers by serving street food from trucks with relatively small start up costs. These new businesses work well in LA because generations of immigration have created a diverse food culture and it's so close to one of the biggest farming regions in the United States. Richard Johnson meets these street food pioneers, tastes a "cheese trilogy" and asks the city's most famous chefs and food writers what else the food future might hold. Producer: Dan Saladino.