In a 5 ½-quart Dutch oven or similar heavy pot, warm the olive oil over medium-high heat. Add the onion, green pepper, carrot, celery and 1 teaspoon salt and cook, stirring only occasionally, until vegetables are beginning to be tender and browned, about 10 minutes.
Add garlic and cook, stirring frequently, for one minute.
Add tomato paste, chili powder, cumin and paprika and cook, stirring, one minute more.
Stir in broth and tomatoes (with all their juices). Bring to a boil, then reduce heat to simmer for 5 minutes. Sauce should be nice and thick.
Add beans and corn (straight from frozen is fine) and simmer until warmed through.
Off the heat, stir in cilantro and lime juice. Serve with shredded cheese, avocado, red onion and sour cream if you like.
