At the Fire Fighting Training school they would demonstrate this with a deep fat fryer set on the fire field. An instructor would don a fire suit and using an 8 oz cup at the end of a 10-foot pole toss water onto the grease fire. The results got the attention of the students.
The water, being heavier than oil, sinks to the bottom where it instantly becomes superheated. The explosive force of the steam blows the burning oil up and out. On the open field, it became a thirty foot high fireball that resembled a nuclear blast. Inside the confines of a kitchen, the fire ball hits the ceiling and fills the entire room.