Step 1: Sauté Aromatics : Heat olive oil in a large pot over medium heat. Add onion and red bell pepper. Sauté for 5–6 minutes until softened. Stir in garlic, cumin, smoked paprika, chili powder, and cayenne. Cook for 1 minute until fragrant.
Step 2: Add Beans and Broth : Add black beans, diced tomatoes, and vegetable broth. Stir to combine. Bring the mixture to a boil, then reduce heat and simmer for 20 minutes, allowing flavors to meld.
Step 3: Blend the Soup : Optional: Use an immersion blender to puree part or all of the soup for a creamy texture while leaving some beans whole for body. Stir in salt, black pepper, lime juice, and chopped cilantro. Adjust seasoning to taste.
Step 4: Prepare Lime Crema : In a small bowl, whisk together sour cream or yogurt, lime juice, and salt until smooth.
Step 5: Serve : Ladle soup into bowls and top with lime crema. Add optional toppings such as avocado, tortilla strips, or extra cilantro.