Among the different ways to thicken, adding less liquid or simmering uncovered to reduce out some liquid are the best ways to keep the flavor of the original recipe. Adding masa harina as a thickener is next best as it will have minimal effect on the flavor. Adding tomato paste or mashed beans may work but will have a significant effect on the taste of the chili.
I have seen masa harina used as a thickener in chili competitions.
Of course, you may like the flavor better with added tomato paste or added beans.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan
STOP NOW!!!! LoL You are making me so hungry!!!! I made some chili 2 or 3 wks ago, way too much, so threw some in the freezer. I promised THAT chili to my dh's workmate. Now I have to go shopping again. Thanks a lot!!! ROFL
I usually drain all the liquids, and use tomato paste.
In order to change the world, one must first start with one's self.
Just like a good Salsa Bolognese, chili needs to be cooked for a good, long time, in my opinion. Mine takes around three hours. LOTS of liquid to begin with, which evaporates during the cooking process. Stir frequently and the liquids will evaporate faster.
Eat the next day!