Collect all the necessary ingredients, ensuring everything is ready for preparation. This step helps streamline the cooking process and ensures you have everything on hand.
In a large skillet, cook the ground beef and chopped yellow onion over medium heat, breaking up the meat with a wooden spoon until it's browned, about 8 minutes. Once cooked, drain any excess fat. This step helps achieve a flavorful, lean base for the soup.
Transfer the cooked beef and onion mixture into a 4- to 5-quart slow cooker. Add the beef broth, chopped potatoes, diced tomatoes, Cheddar cheese soup, tomato paste, ketchup, and mustard. Stir everything together to ensure the ingredients are well mixed, creating a flavorful base for the soup to develop as it cooks.
Cover the slow cooker and cook on Low for 9 to 10 hours, or on High for 4 1/2 to 5 hours, until the potatoes are soft and tender. This slow cooking allows the flavors to fully meld together, creating a rich, comforting soup.
Mix the shredded Cheddar cheese into the soup, stirring until it melts and creates a creamy, cheesy texture. This adds richness and enhances the flavor, making the soup even more indulgent.
Top each serving with a garnish of dill pickles, red onion, extra shredded cheese, and a drizzle of ketchup and mustard. These fresh, tangy additions enhance the flavor and give the soup a fun, cheeseburger-inspired finishing touch.