In a large pot over medium heat, cook onion, garlic and olive oil until onions are transparent and garlic is fragrant.
Add mushrooms and cook until softened.
Pour can of diced tomatoes into the pot and let simmer. Rinse and drain beans and add to pot.
Add red, green and jalapeno peppers and pearl barley, stir to incorporate.
In a separate bowl, mix together the spices: cumin, cinnamon, garlic powder, onion powder, flour, chili powder, chili flakes and pepper. Add to the pot and stir. Let cook for 3-5 minutes and give it a taste. Add salt to taste.
Lower the heat to 2 or 3 and let chili simmer for 30-45 minutes. You'll see all the vegetables cook and meld together and become some sort of uniform stew. The barley will need about 30 minutes to fully absorb the liquid. Stir occasionally to keep any of the ingredients from burning at the bottom.
Spoon out and enjoy! Chili gets better the next day because all the spices settle into everything. It makes things much more delicious.