200g/6oz good steak per person (OK, at a push you can use good-quality mince)
1 tbsp. soy/Worcestershire sauce
1 tbsp. tomato ketchup
freshly ground pepper

1. Trim some (but not all) the fat from the steak.  (A hamburger should have a fat content of about 10%-20% to make it moist when cooked – less fat than that makes it a little dry).
2. Grind the steak in a food processor or other chopper (or get the butcher to do it for you).
3. Mix in the ketchup, soy/Worcestershire sauce and pepper.
4. Divide the mixture into equal parts.
5. Roll each portion into a ball in your hands.  Flatten with your hands on a surface, making them about ¾” thicker if you like them underdone, or thinner for well done.
6. Cook on a HOT barbecue or griddle for about 2 minutes each side (medium), less for rare, or more for well-done.