Heat olive oil in a large pot or Dutch oven over medium heat. Add the onion and cook until softened, about 5 minutes.

Add the minced garlic and cook for another minute until fragrant.

Add the ground chicken to the pot and cook, breaking it up with a spoon, until browned. Drain off any excess grease.

Stir in the diced tomatoes (undrained), black beans, corn, diced tomatoes and green chilies (undrained), chicken broth, chili powder, cumin, and cayenne pepper (if using).

Season with salt and pepper to taste.

Bring the soup to a boil, then reduce heat and simmer for 15-20 minutes, or until the flavors have melded.

Serve the soup hot, topped with shredded cheddar cheese, tortilla chips, sour cream or Greek yogurt (if desired), and chopped cilantro (if desired).