DaveReidUK (post number 10).
I forwarded your message to Boeing. They've replied that the 787 battery system has proven to be more than capable of toasting Bread, Muffins and even a Kelloggs Pop Tart. Carbon Fibre has proven to be marginally less successful but the new stainless steel box will gentle radiate enough heat to toast a slice of Kingsmill Nutty Brown at a range of 5 feet (and is also rated for frying a slice for breakfast should the need arise.)
With 2 crew it should be possible to get the FO to slap the bread down, race back to the flightdeck, make a radio call, perform a fuel check and still be back in time to prevent the same sort of light scorching shown in those NTSB photos.