Some people prefer to cook with natural gas. Others prefer to cook with electricity. In rural Congo, wood is the main cooking fuel. Wood is a plentiful fuel in Congo. However, other fuels are healthier like charcoal.
But the best fuel is the sun. However, solar cooking is not practiced or used. Solar cooking would probably add too much time to the cooking process.
Solar cooking is practiced in many other countries in Africa due to a limited and distance supply of wood. A 12-hour day, 365 days a year is an endless fuel.