This copycat version of Wendy's Chili can be made up to three days in advance so you can prep it on the weekend for weeknight dinners.
Heat a large Dutch oven or stockpot over medium-high heat. Add the beef, breaking it into small pieces with your hands as you add it to the pot. Cook, stirring occasionally to break the beef into small chunks, until fully browned. Spoon the beef into a bowl and set aside. Reserve the beef drippings in the pot.
Reduce the heat to medium and add the onion, celery, and bell pepper to the pot. Cook, stirring occasionally, until the vegetables are very tender and translucent, about 10-15 minutes.
Stir in the chili powder and 3/4 teaspoon salt, then return the beef to the pot along with the beans, diced tomatoes, tomato sauce, and broth. Cover and bring to a simmer, then uncover and reduce the heat to medium low.
Cook for at least 1 hour to 90 minutes, stirring occasionally, to allow the flavors to meld. Taste and add more salt as needed.
MAKE-AHEAD: Chili can be made up to 3 days in advance.