Have you tried a little bit of espresso grounds? It adds a certain flavor to meats that’s just… incredible… Might not go with what you have here though.
Or like tap out the tiniest amount of cinnamon on your hand and add whatever falls off of it? It shouldn’t even be enough to say there’s cinnamon in it. It’s like nature’s msg, it just makes it taste better, gives it a good homogeneous flavor that pops somehow. Straight up witchcraft
The thing with the cinnamon is you’re not adding anywhere close to enough to taste it. Not even really enough to say that it’s in there. It’s like the bay leaves in this thread, adding the most miniscule amount to a recipe does something to the flavor. It’s not enough cinnamon for it to logically be the cinnamon but it just tastes better somehow.
I’m not a coffee person at all either. So that’s totally understandable.
Soy sauce is a surprisingly adaptable ingredient!