To make a roux, combine butter and flour in a big pot and stir constantly for two minutes.
Add spices and beef broth while whisking ferociously. Slowly pour in half the beef broth. This will aid in avoiding lumps. Add the remaining beef stock, the onion, the garlic, the beef bouillon base (if using), and the bay leaf after the mixture is smooth and lump-free (if using).
Until the gravy is smooth and thick, give it about 3 minutes to simmer. Add salt and pepper after tasting. Enjoy!