In fact, they were so good I still make them now. What impressed me at the time was the inventiveness of my mother and that they came with a hidden surprise - a deliciously gooey core of cheese.
300 grams beef mince
1 small red onion
1 small carrot
1 stalk celery
handful parsley leaves
1 heaped tablespoon tomato paste
freshly grated parmesan
salt and pepper
cheese, cut into cubes (Swiss and Cheddar are my favourites)
I take after my mother and prefer to mince my own beef - in this case I use girello, which is a very lean meat. You could equally use rump or topside.
You can chop the vegetables and parsley by hand into a very small dice or go for the time saving option and use a processor to get them nice and fine.
Place the mince and the prepared vegetables into a bowl, along with a heaped tablespoon of tomato paste and a generous handful of grated parmesan. Sprinkle over with a little sea salt and white pepper and then mix this together until evenly distributed - this is best done my hand. This also helps to work the proteins of the meat so the patty will stick together.
Divide the mixture evenly into 6 to 8 portions, depending on the size of hamburger you like. Remeber that these are going to be filled so they will be thicker than a normal hamburger. If you want to be pedantic, use a scale to get even-sized portions.
Take a portion roll it around in your palm to form a ball - flatten the ball in your palm and place a cube of cheese in the centre. Fold up the sides to cover the cheese and reshape to form a patty.
Repeat this process until all portions have been formed.
Place some breadcrumbs into a dish and take a patty and roll this round the crumbs to lightly coat. The crumbs help form a nicer crust.
You can now store these in a sealed container in the fridge until ready to cook.
Place a knob of butter and a little oil in a frying pan and place over a medium heat. When the butter has melted and has started to sizzle, add in the burgers, being careful not to crowd the pan. Brown both sides then transfer onto a baking paper lined tray.
Bake, in a pre-heated 180°C oven until cooked through - about 20 minutes depending on size. Turn them over half way through the cooking time.
They are moist and far more tasty than plain old hamburgers. These weren't eaten in buns but as a companion to various vegetables. However, leftovers were surprising tasty eaten cold in rolls.