Brown the ground beef. Heat the olive oil in a large pot over medium-high heat. Add the ground beef and cook for 6–8 minutes, breaking it into medium-sized crumbles, until nicely browned. Spoon off any excess grease if needed.
Cook the vegetables and spices. Add the diced onion and red bell pepper to the beef. Cook for 4–5 minutes, until softened. Stir in the garlic, chili powder, smoked paprika, cumin, and oregano. Cook for another 30 seconds, until fragrant.
Simmer the potatoes. Pour in the beef broth, scraping up any browned bits from the bottom of the pot. Add the potatoes, salt, and black pepper. Bring to a gentle boil, then reduce the heat, partially cover, and simmer for 8–10 minutes, until the potatoes begin to soften.
Add the tomatoes. Stir in the diced tomatoes with their juices, tomato sauce, and Worcestershire sauce. Bring the soup back to a gentle simmer and cook for another 2–3 minutes.
Add the beans and corn. Stir in the drained pinto beans, kidney beans, and frozen corn. Simmer uncovered for another 8–10 minutes, or until the potatoes are completely tender and everything is heated through.
Finish with cheddar. Turn off the heat and stir in the shredded cheddar until melted. Taste and adjust the salt and black pepper if needed. Let the soup rest for 20–30 minutes to allow the flavors to settle.
Serve. Ladle the Cowboy Soup into bowls and garnish with chopped fresh parsley or green onions, if desired. Serve warm with crusty bread or cornbread.