Isaan is the Northeast of Thailand, with about 22 million people. Isaan is poorer than the rest of Thailand, because it consists of a plateau that holds less water than the fertile plains of especially Central Thailand. The inhabitants of Isaan are closely related to the Lao people in Laos, and speak basically the same language.
Many of the Isaan are migrant workers. Some seasonal, and they come back for planting and harvesting the rice. Other are permanent migrants working in Bangkok and other industrial areas. Many Isaan work for stints as labourers overseas in e.g. Taiwan, Singapore, and Israel. Tens of thousands of Isaan women have married foreigners and are living abroad.
Within Thailand, the Isaan are famous for making anything into food. Herbs and leaves from around the house provide the needed vegetables, and e.g. beetles, lizards, and red ants eggs are common parts of Isaan dishes.