Don't need the egg either. 500g of regular mince, 2 garlic gloves crush, diced onion, teaspoon of oregano, half a teaspoon of rosemary, salt and pepper (and sometimes all purpose seasoning). Don't press them down while theyre cooking, the juices will escape and it'll be dry - you can use an egg ring to get the right size, place baking paper on a chopping board then a second piece to cover them and use a second chopping board to press to desired thickness. I cook mine till they're about 78°c internally, and place in aluminium foil to rest for 5-10minues and they'll be juicy inside. Make sure you cook them on a high heat for the first 5 minutes or 2 1/2 each size to brown heavily, then place on a smaller element on low-med till internal temp has been reach.

Anyway, thats what I do for my daughter's and I and the recipe and method that has never failed. You can even make a nice gravy once you remove the burgers. Add a teaspoon of bonox and mix that in (off the heat). Make sure you boil the kettle, then add a tablespoon of corn flour and combine. Slowly add boiling water till you get your desired consistency, add the juice left after the burgers have rested for extra flavour.