parch, roast
熬 centers on applying dry heat to food: parching grains or roasting something until it is dry and cooked through.
熬 combines 敖 (a phonetic component suggesting 'proud' or 'roam') with 灬 (fire), indicating cooking with fire. The exact historical development of the phonetic choice is uncertain.
The top 敖 looks like a person standing proudly, and the bottom 灬 is fire. Imagine someone proudly roasting grains over a fire until they are parched and dry.
For ゴウ, picture a proud chef roasting grains and shouting 'Go!' (ゴウ) as the fire flares up: Go -> ゴウ, and the grains parch perfectly.