Prepare the chili by heating the olive oil in a large Dutch oven over medium heat. Add the onion, celery, poblano, and bell pepper, then cook, stirring often, for 4-5 minutes or until softened.
Add the minced garlic, cumin, oregano, chili powder, coriander, paprika, sea salt, and freshly cracked pepper, to taste. Stir constantly so the veggies get evenly coated with spices and cook for 1 minute.
Add the tomato paste, black beans, crushed tomatoes, and chicken broth.
Stir until mixed well, then cover with a lid and place in the oven for 3½ hours, stirring occasionally. Side Note: For slow cooker Instructions–cover and cook on low for 6 hours or on high for 3 hours.
Remove the Dutch oven from the oven and add the chopped-up corn tortillas (they add great flavor and thicken the chili).
Cook over medium-low heat until the corn tortillas dissolve, about 30-40 minutes.
Grill the chicken by heating a little more oil in a grill pan over medium heat.
Season the chicken breasts with sea salt and freshly cracked pepper, to taste.
Add to the grill pan and cook for 6-7 minutes on each side, or until cooked through.
Let the meat rest for at least 5 minutes before cutting it into bite-sized chunks.
Stir in the grilled chicken.
Serve the chili topped with sour cream, green onion, cilantro, fresh avocado, shredded cheese, tortilla chips, and hot sauce, if desired. Enjoy!