Step 3
Heat the vegetable oil in a skillet over medium heat. Stir in the green bell peppers, celery, and chopped onion; cook and stir until the onion has softened and turned translucent, about 5 minutes. Stir onion mixture into the stock pot. Increase the heat to medium-high and bring to a near boil. Mix in the kidney beans, white beans, and black beans. Season with chili powder, brown sugar, cumin, paprika, Italian seasoning, vinegar, basil, dried minced onion, parsley, red pepper flakes, oregano, hot pepper sauce, salt, and pepper. Reduce heat to medium-low and simmer for 1 hour 30 minutes, stirring often.