In a large stockpot or Dutch oven, heat the olive oil over medium-high heat. Add the ground beef, pressing it into the bottom of the pot to form one large patty. Let it brown undisturbed for 8 to 10 minutes, until a flavorful crust forms on the bottom.

Use a wooden spoon or spatula to break the browned beef into crumbles. Continue cooking for another 5 minutes, or until the beef is no longer pink.

Stir in the finely chopped celery, diced onion, and diced green bell pepper. Cook for about 5 minutes, or until the onion turns translucent and the vegetables begin to soften.

Add the stewed tomatoes, tomato sauce, diced tomatoes with green chiles, and water. Use your spoon to gently break apart any large tomato chunks for a more even chili texture.

Stir in the mild chili seasoning mix. Add the undrained kidney beans and undrained pinto beans. Season with salt and ground black pepper to taste, then stir well to combine.

Bring the chili to a gentle boil. Reduce the heat to low, partially cover the pot, and simmer for 1 hour, stirring occasionally to prevent sticking and to develop deeper flavor.

Just before serving, stir in the white vinegar. Taste and adjust with more vinegar, salt, or pepper if desired.

Serve hot with your favorite toppings, such as shredded cheddar, diced onion, sour cream, tortilla chips, jalapeños, avocado, or hot sauce.