Rinse and drain garbanzo beans, black beans, and kidney beans. Transfer to a 6½ quart slow cooker.
Chop onions and mince garlic.
Peel sweet potato and chop into large chunks.
Wash cauliflower and divide into florets.
Transfer onions, garlic, potato, and cauliflower to slow cooker.
Stir in diced tomatoes, tomato sauce, allspice, cumin, turmeric, chili powder, ginger, oregano, salt, and pepper. Cook on high for 6 hours. Stir in coconut milk.
Just before serving, pull leaves from cilantro and chop. Cut limes into wedges.