Combine 2 cups water, the beans, chicken broth, vinegar, onion, bell pepper, garlic, bay leaf, cumin, oregano, 1 1/2 teaspoons salt and a few grinds of pepper in a 6- to 8-quart slow cooker. Cover and cook on low until the beans are tender, about 8 hours.
Discard the bay leaf. Working in small batches, puree about half of the soup in a blender. Stir the pureed soup back into the slow cooker. Season with salt and pepper.
Cook the chorizo in a small nonstick skillet over medium heat, stirring occasionally, until lightly browned, about 5 minutes. Top each serving of soup with the chorizo and toppings.