Start by heating the vegetable oil in a large pot over medium heat. Add the ground beef and cook it until it's browned, breaking it up into small pieces as it cooks. This should take about 5-7 minutes.
Once the beef is browned, add the chopped onion, celery, and green bell pepper. Sauté them with the beef for about 5 minutes, until the onions become translucent.
Stir in the diced tomatoes (with juice), kidney beans, and black beans. Mix everything to ensure the ingredients are evenly distributed.
Pour in the beef broth and add the tomato paste. Stir the mixture until the tomato paste is fully dissolved, giving the chili a rich, thick consistency.
Add the chili powder, ground cumin, paprika, cayenne pepper, dried oregano, sugar, salt, and black pepper. Stir well to ensure the spices are evenly incorporated.
Reduce the heat to low, cover the pot, and let the chili simmer for about 30-40 minutes. Stir occasionally to prevent sticking and to allow the flavors to meld together.
After simmering, taste the chili and adjust the seasoning as needed. You can add more salt, cayenne pepper, or vinegar to suit your taste.
Once the chili is ready, serve it hot. You can enjoy it on its own or top it with shredded cheese, sour cream, or chopped green onions.