Add the cauliflower to a food processor and pulse it until it forms small pieces that resemble ground meat. Set it aside.
Repeat the same steps with the walnuts.
Heat the oil in a large pot over medium heat. Add the onion and bell pepper, and cook for 3-5 minutes, until the onion is translucent. Add the spices and salt, and cook for another 1-2 minutes, until the spices become fragrant. Make sure to stir it often to keep the spices from burning.
Add the rest of the ingredients and bring it to a boil. Reduce the heat and simmer for 30 minutes.
Spoon your chili into a bowl, add your favorite toppings, and enjoy!