Sauté the aromatics: Heat olive oil in a large pot or Dutch oven over medium heat. Add onion and bell pepper. Cook 5–7 minutes until softened.
Stir in garlic and jalapeño; cook 1 minute until fragrant.
Bloom the spices: Add chili powder, cumin, smoked paprika, oregano, cayenne (if using), salt, and pepper. Stir for 30–60 seconds to toast the spices. This step builds deep flavor.
Add tomato base: Stir in tomato paste and cook 1–2 minutes until it darkens slightly.
Add diced tomatoes and chicken broth, scraping the bottom to release any browned bits.
Nestle in the chicken: Submerge the chicken breasts in the liquid. Bring to a simmer, then reduce heat to medium-low. Cover and cook 15–20 minutes, until the chicken is cooked through and tender.
Shred the chicken: Remove chicken to a board and shred with two forks.
Return it to the pot along with the beans and corn (if using). Simmer uncovered 10–15 minutes to thicken and let flavors meld.
Adjust texture and seasoning: For a thicker chili, mash a ladleful of beans against the side of the pot or use an immersion blender for 2–3 quick pulses. Taste and add more salt, pepper, or cayenne as needed.
Brighten and serve: Stir in lime juice and a handful of cilantro.
Ladle into bowls and add your favorite toppings.