Step 1: In a large pot or Dutch oven, brown the ground beef over medium-high heat. Break it into small crumbles as it cooks. Once fully browned, drain any excess fat and set the beef aside.
Step 2: In the same pot, add the diced onion and celery. Sauté for 5-7 minutes until softened. Add the minced garlic and cook for another minute until fragrant.
Step 3: Return the browned beef to the pot with the sautéed vegetables. Stir in the diced tomatoes, tomato sauce, kidney beans, pinto beans, beef broth, and water. Add chili powder, cumin, smoked paprika, oregano, salt, black pepper, cayenne pepper (if using), and sugar. Stir everything together thoroughly.
Step 4: Bring the chili to a gentle boil, then reduce the heat to low. Cover and let it simmer for at least 1-2 hours, stirring occasionally, to allow the flavors to deepen.
Step 5: After simmering, taste the chili and adjust seasonings as needed. Serve hot with your favorite toppings.