These burgers are 'naked' purely because they have no salt and pepper - you can add as much or as little as you want, or no salt at all.
Remember the secrets of a good burger are to use minced (or ground as the Americans call it) chuck steak. An 8mm mincing plate size is perfect. Use meat that has a minimum of between 15% - 20% fat content, and make sure you mince the meat twice, then mix together well: they will bind easier and the burger will hold its fat and moisture better.
1. Just mix well together, and add salt and pepper if you want to.
2. Roll into 6 equal balls, and then flatten.
3. Very lightly oil the burgers on both sides, also lightly oil the hot grill bars using kitchen towel.
4. Grill for 2-3 minutes, then turn 90° and continue to cook for a further couple of minutes.
5. Flip over and cook for the same amount of time. Do not overcook.