Well the first time happened whilst camping, the pan had had lots of oil in it and a few different kinds (no like lamp oil, just cooking oils). It was above a hot fire, because the temperature had got down to -1C in the night and the water was almost frozen. The flames licked over the edge and the surface of the water, I pulled it out of the fire and left it sat on the ground for a few seconds until it burnt out. We soaked the wood in lighter fluid, so if it was just the fumes gathering in the air pocket or something I don't know.

The second time was less mysterious. The pan had been used for a flambé the night before, I just added water and put it on the heat. I believe I flambé'd water . . . still tasted like water, no new beverage discovery.