Notice how some of these tomatoes have unripe-looking tops? Those "green shoulders" are actually the keys to flavor. pocius/Flickr.com hide caption

itoggle caption pocius/Flickr.com

Vietnam has contained the fatal bird flu cases that raged in the late 2000s, but it is still struggling with new cases of the virulent disease. Here, a poultry trader loads live chickens onto his motorbike on March 16 at a market outside Hanoi. Hoang Dinh Ham/AFP/Getty Images hide caption

itoggle caption Hoang Dinh Ham/AFP/Getty Images