Heat olive oil in large saucepan over medium-high heat. Add onion, bell peppers, carrots and 1/2 teaspoon salt; cook, stirring frequently, until the carrots begin to soften, about 8 minutes.
Add garlic and cook 2 more minutes.
Add chili powder, cumin, coriander, oregano, chipotle, tomato paste and tortillas and cook, stirring, until tomato paste is brick red, about 4 minutes (add a splash of water if the mixture begins to stick).
Add coffee and simmer until almost completely reduced, about 30 seconds.
Stir in tomatoes, cocoa powder, beans and 2 1/2 cups water and bring to simmer over low heat. Cook, stirring occasionally, until chili thickens slightly, about 1 hour, 30 minutes.
Meanwhile, trim large stems off cauliflower and coarsely grate the florets on a box grater. About 10 minutes before chili is done cooking, stir in grated cauliflower. Cook 10 minutes, then remove from heat.
Stir in chopped cilantro and season with salt. Add some water if the chili is too thick.
Ladle into bowls and add toppings (i.e., cheese if desired).