A lot of London Broil recipes can come out tough if they are not cooked correctly. This means that you have to know how to make a London broil for it to be tender. The cuts sold as London Broil are generally leaner cuts of beef without a lot of intramuscular fat and can dry out if they are overcooked. When you slow cook this London broil recipe low and slow with plenty of gravy, it stays moist and juicy.