If you reeeeally wanna go as far as you can, you'd have to start with the very first humans who even figured out you can light food on fire to make it gooder
All cooking methods have evolved from one another, some by logical progression, some by being introduced brand new from another culture, but the idea of tossing edible stuff in a hot metal container, filling it with a fat or oil which is likely alrady known to heat up hotter than water, and waiting till it gets tasty, is something many cultures developed independently