"Cooking on the Banjo" *LINK*

I have heard of other instances of cooking in the firebox; though the others you mentioned are new to me.
Chinese QJ class locomotives had a box near the firebox and cab. There was some question about what they were for, but I think the concensus was that they were used for heating meals.
My dad, an old oilfield hand (later petroleum engineer), talked about heating coffee and food on the engine of the car while out in the field. He had a can of beans explode one time when he did that!
Brad Smith's video of stationary steam engines in the Gulf Coast area of the US showed the plant engineer heating up coffee and food on top of the mill's stationary engine.
My dad also told me about memories back when drilling rigs were steam powered. One time, they had worked all night on a well, trying to keep it from blowing. When dawn broke, my dad took a dive in the pit used as feedwater for the rig's boilers. This greatly upset the engineer, since he stirred up the sediments!
He also talked about lying in the crew bunk at night, tracking the progress of the rig from the sounds of the various steam engines. The family of a former boss at a computer store had a family-owned sugar mill once ran by steam engines; he said you could tell how much cane was being ground by the sound of the plant's steam engine.
Way off topic, but more memories from the the era of steam.
-James Hefner
Hebrews 10:20a