Put all the ingredients for a burger mix, except an olive oil, in a big bowl. With clean hands, mix everything up well. Divide into and pat and mould each piece into a 4 roundish shape about 1 - 1 1/2 inches thick. Drizzle the burgers with oil, put on a tray, cover and place in the fridge until needed. Preheat a large griddle or frying pan for about 3-4 minutes on a high heat. Turn the heat down to medium. Place the burgers on the griddle or in the pan and cook them until golden brown, about for 3 or 4 minutes on each side. Please do not overcook them. While your patties are cooking, halve your burger buns, spread some butter on each half and toast them on a grill, just for a 1 minute. When everything comes together pop your burgers on to their buns, add all the toppings you want, your homemade or store bought ketchup and enjoy!