1. Cook the Chicken (If Using):Add oil to a large ceramic, stainless steel, or or cast iron saucepan over medium heat and heat for 1 minute. Saute the onion and red pepper for 1-2 minutes.
2. Add the chicken and cook for 3-5 minutes, stirring occasionally, until no longer pink.(For vegetarian or vegan versions, skip this step and move to Step 3.)
3. Build the Soup Base:Add broth, corn, black beans, diced tomatoes with green chiles, jalapeño, cilantro, chili powder, and cumin to the saucepan. Stir to combine.
4. Simmer for Flavor:Bring the mixture to a boil, then reduce the heat to low. Let the soup simmer, uncovered, for 20 minutes to allow the flavors to meld together.
Serve and GarnishLadle the soup into bowls and top as desired with shredded toasted corn tortillas, plain yogurt or feta, avocado slices, and diced green onions. Finish with a squeeze of fresh lime and a sprinkle of chopped cilantro.