Brown the sausage in a large pan over medium heat for 8-10 minutes until no longer pink. Remove from heat and drain excess fat from the pan. Transfer the sausage to slow cooker crock.
Deglaze the pan over medium-high heat with chicken or vegetable stock, scraping up browned bits from the bottom of the pan with a wooden spoon.
Add olive oil, garlic, and onion to the pan and sauté for 3-4 minutes, stirring frequently, or until softened.
Add celery and carrot and continue cooking for another 2-3 minutes, or until softened. Remove from heat and pour pan contents into the slow cooker.
Add white beans, red beans, tomato sauce, tomato paste, petite-cut tomatoes, chili powder, cumin, oregano, and cayenne pepper to slow cooker. If desired, add black coffee or water to thin out the mixture before cooking. Season with salt, to taste, and stir to combine.
Cover and cook on high for 4 hours, or low for 8 hours. When complete, taste and adjust seasonings, as desired.
To serve, spoon chili into individual serving bowls and top with shredded cheese, chopped onions, and/or sliced jalapeno peppers, as desired. Enjoy!