Pit smoker, doable without building walls?

[JP_Finn]

I’ve been trying to figure out a way to build a smoker/smoke house without 54 logs, 20 boards and 4 slender trunks.
Had an idea to dig 2 adjacent pits, then mod a structure to include roof, walls and fireplace.
But the placement of “walls” (packed earth) in soil... won’t work as walls.
I’m not sure if the idea is doable or not. So, can anyone think of a way for the idea to work at all without needing to build the walls tile by tile?