Heat 1 tablespoon olive oil in a large Dutch oven over medium-high heat. Add 1 pound chorizo and cook, breaking up as you go, until no longer pink.
Add 1/2 cup diced onion,1 small jalapeno, seeded and diced, 1 red bell pepper, diced and 2-3 cloves garlic and cook until the vegetables are tender, 5-7 minutes.
Stir in 1 4 oz. can tomato paste and cook until the mixture is a dark red, 5-7 minutes more. Slowly pour in 6 cups chicken broth and stir until the tomato paste is completely incorporated. Stir in 2 teaspoons chili powder, 1 teaspoon oregano, 1/2 teaspoon cumin and 1 tablespoon brown sugar.
Add 1 15 oz. can black beans, rinsed and drained and 1 15 oz. can pinto beans, rinsed and drained. Stir in 2-3 cups cooked shredded chicken. Season with salt and pepper, to taste. Simmer for 20-30 minutes to blend the flavors.
Stir in chopped fresh cilantro just before serving, topped with your favorite chili toppings.