Cook the ground beef and onion in a large Dutch oven or soup pot over medium heat until the beef is browned and the onion is tender. Drain excess grease if needed.1 pound ground beef,1 cup diced onion.
Add the butter and stir until melted. Sprinkle the flour over the beef mixture and cook for 1 minute, stirring constantly.4 tablespoons butter,1/4 cup all-purpose flour.
Gradually stir in the chicken broth. Add the potatoes, Worcestershire sauce, garlic powder, salt and pepper.3 1/2 cups chicken broth,4 cups peeled and diced potatoes,1 tablespoon Worcestershire sauce,1 1/4 teaspoons garlic powder,1 1/4 teaspoons salt,1/4 teaspoon black pepper.
Bring the soup to a gentle boil, then reduce the heat and simmer for 12 to 15 minutes, or until the potatoes are fork-tender.
Reduce the heat to low and stir in the heavy cream. Cook for 2 to 3 minutes, until heated through. Do not boil.1 1/2 cups heavy cream.
Add the cheddar and Monterey Jack a handful at a time, stirring after each addition until melted and smooth.2 cups shredded sharp cheddar cheese,1 cup shredded Monterey Jack cheese.
Ladle the soup into bowls and top with crumbled bacon, additional shredded cheddar cheese, and sliced green onions, if desired.Cooked, crumbled bacon,Additional shredded cheddar cheese,Sliced green onions or chives.
Notes
Pro Tip: Shred the cheese from a block and add it a handful at a time over low heat. This helps it melt smoothly into the soup without becoming grainy.