Cook the Ground Beef: In a large pot, brown the ground beef over medium heat, breaking it up with a spoon until fully cooked. Drain any excess fat.
Sauté the Vegetables: Add the chopped onion and garlic to the pot with the beef. Sauté for 3–4 minutes until softened and fragrant.
Add the Broth and Potatoes: Pour in the beef broth, and stir in the diced potatoes. Bring the mixture to a boil, then reduce heat and simmer for 15–20 minutes until the potatoes are tender.
Stir in the Dairy: Lower the heat and add the shredded cheddar cheese, milk (or heavy cream), and sour cream. Stir until the cheese is fully melted and the soup becomes creamy.
Season to Taste: Add salt and pepper to taste, adjusting to your preference.
Serve: Ladle the soup into bowls and top with optional garnishes like crumbled bacon, pickles, or fresh herbs.