I also use just a teaspoon or so of black cocoa powder in beans and chili, for the same reason, especially when I’ve used my homemade tomato sauce, which is just a little too bright tasting. It also is an amazing thickener, BTW. It darkens the sauce and a little goes a long way.
I think of it as the *mole school* of flavor blending.
Now, New Mexico roasted green chili gravy? I have that down, thanks to a toothless little old geriatric that was much more comfortable with me when I took my teeth out too.
Only problem was she didn't speak spanish or english, except a few words. I don't know what language she was speaking. But we communicated in the kitchen.
I got extra points because I can keep a wood cook stove at an even temp.
/johnny