Preheat oven to 375 degrees. Toss bread with olive oil, garlic powder, and salt and pepper to taste on a rimmed baking sheet. Bake 10 to 15 minutes or until golden brown and fragrant.
Meanwhile, in a Dutch oven or stock pot, cook ground beef until mostly browned, about 5 minutes. Drain if desired (see notes).
Stir in garlic until fragrant, about 30 seconds. Add beef broth, onions, carrots, celery, potato, tomatoes, Worcestershire sauce, Kitchen Bouquet (if using), and bay leaf.
Bring to a boil and simmer uncovered for 30 minutes. Remove bay leaf and season to taste with salt and pepper (I like 1 tablespoon of salt and 2 teaspoons pepper).
Serve the soup with croutons and shredded cheese for garnish.