In a large bowl combine ground beef, breadcrumbs, dry mustard, 1 teaspoon beef bouillon, 2 teaspoons Worcestershire sauce, ketchup, salt, pepper. Mix well and form the mixture into 8 patties.
Heat vegetable oil in a large deep skillet over medium-high heat. Add the beef patties and cook until both sides are browned. Remove from the pan.
Add the onions and cook for several minutes, until very soft, stirring occasionally. Add the minced garlic and cook while stirring for 1 minute.
Add 2 tablespoons of flour and whisk constantly for 1 minute or until the flour begins to turn brown.
Add beef broth, 2 teaspoon Worcestershire sauce, 1 teaspoon beef bouillon, and 1 tablespoon ketchup. Keep whisking for a minute and then add the hamburger steaks back to the pan.
Cover and simmer on low for 20 minutes or until the hamburgers are fully cooked (the internal temperature has reached 165 degrees F.), adding additional beef broth if the gravy becomes too thick.