This may be anecdotal.
Playing in the kitchen I realized the frying pan comes with both a flat, and a concave bottom. So here's the question –
Given two pans made of brass, one has a concave base & the other a flat base, which of the two would use heat more efficiently? I would believe the latter because the flat base means any heat must necessarily travel through the cooking medium, and the recipe before reaching open air.
Best Answer
The Wok
is a design that gets the maximum efficient use of energy for cooking and needs a minimum of heat source.
A flat bottom equivalent pan transfers the heat to the food from the bottom plane, and the walls are just containers radiating most heat away, since the food is at the bottom. A Wok focuses the heat from the walls to the food being cooked ( think of a parabola and its focal point). The walls partake in the cooking process effectively giving more area contact to the food than the flat bottom one.