Soak the beans overnight or use a quick-soak method*. Drain the beans and put them into a pressure cooker, crockpot, or large chili pot. Add the vegetable broth (5 cups for pressure cooking, 6 for crockpot and stove) and all ingredients through chili powder. Begin heating over high heat. (Use the sauté button on the Instant Pot.)
Heat a non-stick skillet. Once it's hot, add the chopped onion. Cook, stirring and scraping the bottom of the skillet, until onion is golden brown, adding a tablespoon of water if necessary to keep it from sticking. (Tip: Add a couple of pinches of baking soda to speed up the caramelization.) Add the onion to the beans.
For Pressure Cooper or Instant Pot
Follow instructions above. Seal the cooker and bring to high pressure. Reduce heat and cook for 10 minutes at high pressure. (On IP, set pressure cooking time to 10 minutes.) When the 10 minutes are up, remove from heat (or turn IP off) and allow pressure to come down naturally For at least 15 minutes before releasing the pressure manually.
Check to make sure beans are soft, and if they aren't, return to high pressure for another minute. Once the beans are soft, add the salt and tomatoes and taste for seasoning. If necessary, add more cumin, pepper, and chili powder. Simmer over low heat for at least 20 minutes (use Saute set to low on IP). Just before serving, add masa harina; stir well and simmer for at least 5 minutes to thicken.
For Crockpot or Slow Cooker
Follow instructions under For All Cooking Methods. Then, cook until beans are completely soft, on high for at least 6 hours or on low for at least 8 hours (crockpots vary, so adjust times as necessary). Add the salt and tomatoes, check seasonings, and cook for at least another hour. Add the masa and cook another 10 minutes.
Follow instructions under For All Cooking Methods. Then, cover and cook on low heat until beans are completely tender, about 1 1/2 hours, adding water as necessary. Add the salt and tomatoes, check the seasonings, and cook for at least 20 minutes. Just before serving, add masa harina, if necessary to thicken; stir well and simmer for at least 5 minutes.
To quick-soak beans in the pressure cooker, cover with two inches of water and bring to high pressure. Cook at high pressure for 1 minute, remove from heat, and allow pressure to come down naturally before draining and using beans. To quick-soak without a pressure cooker, cover beans with 2 inches of water and bring to a boil. Boil for one minute. Cover and let stand for 1 hour before draining and using beans.This is a zero-points recipe on Weight Watchers Freestyle if you use a fat-free vegetable broth or water.