In a large skillet, heat oil over medium-high heat. Add ground beef and season with salt and pepper. Press the beef down into the pan to make a really big patty. Cook the beef until it begins to caramelize on the bottom. Then break up the ground beef and continue cooking until no longer pink.
Drain any grease from the skillet and transfer the cooked beef into a 6-quart slow cooker.
Add celery, onion, green pepper, stewed tomatoes, tomato soup, water, and tomato sauce to the slow cooker. Stir to combine, breaking up the stewed tomatoes with the spoon as you stir.
Add chili seasoning, kidney beans, and pinto beans to the slow cooker and stir.
Put the lid on the slow cooker and cook on LOW for 6 - 8 hours or on HIGH for 4 - 6 hours without removing the lid. This chili will be thin at first and will thicken upon standing once the heat is turned off. If you like a thicker chili, remove the lid during the last hour of cooking, turn the temp to HIGH, and stir occasionally to allow some of the liquid to evaporate.
Check the seasoning and add salt and pepper to your taste.
Portion into bowls and garnish with shredded white cheddar cheese and a jalapeno slice or two. Serve warm.