Heat a cast iron skillet over medium-high heat and brown the ground beef with the diced onion for 8 minutes, stirring until the beef is no longer pink and the onion is softened (visual cue: browned beef and translucent onion). Drain the beef, then add the minced garlic and cook for 30 seconds until fragrant (visual cue: garlic becomes aromatic but does not brown).

In the crock pot, layer the thinly sliced potatoes, the browned beef mixture, the drained kidney beans, the uncooked long-grain white rice, and the sliced celery in even layers (visual cue: layered bands you can see through the top).

In a bowl, whisk the tomato soup, diced tomatoes, beef broth, chili powder, salt, and black pepper until smooth, then pour the mixture over the layers (visual cue: top is fully covered with red broth).

Cover and cook on LOW for 6-7 hours until the potatoes and rice are tender (visual cue: potatoes yield when pierced and rice looks tender throughout).

Stir gently to combine, then top with shredded cheddar (visual cue: cheese melts from the top as it warms).

Cover and cook 10 minutes until the cheese melts, then serve hot (visual cue: cheddar is fully melted and slightly pooled over the stew).