Heat olive oil in a large pot over medium-high heat. Add diced red onion and chopped bell pepper, stirring frequently for about 4 minutes until softened.

Stir in minced garlic cloves and cook for an additional 2-3 minutes until fragrant.

Pour in chicken stock and add drained black beans, ground cumin, garlic powder, dried oregano, chili powder, salt, and pepper. Stir well, bring to a boil, then reduce heat to medium-low and simmer for 10-15 minutes.

Using an immersion blender, purée about one-third of the soup until smooth, then return the mixture to the pot.

Add sliced smoked sausage and heat on medium for an additional 5 minutes.

Serve in bowls, garnished with fresh cilantro, sour cream, and diced red onion if desired.