The Minion Method is a technique to create a long burning charcoal fire for cooking BBQ.
A basket is filled with charcoal then several of the top pieces are lit. As the lit pieces burn down they in turn light more charcoal.
The rate of burn and thus the smoker or grill temperature is controlled by adjusting the air intake. More air and the fire will burn quicker and hotter.
This technique is often used in Ugly Drum Smokers (UDS), WSMs and Offset Smokers.