How to make
Heat the milk, water and butter in a suitable pan at a moderate temperature to melt the butter. Separately mix 3.5 oz (100 g) of flour, yeast, sugar, salt and egg. Add the milk-butter mixture.
Mix well and start adding flour and stir until you get a soft dough. Knead the dough into a ball and place it in a bowl, cover and leave to rise in the heat and double its volume.
When done, make balls the size of a walnut, flatten them and place them in a tray lined with baking paper. Leave them to rise for another 15 minutes. Spread on them the beaten egg and sprinkle with sesame seeds. Bake them in a preheated oven at 370°F (190 degrees) for 15 minutes.
Mix the minced meat with the egg, breadcrumbs, onion, fizzy water and all the listed spices. Form small burgers by measuring them to the size of the buns.
Keep in mind that the buns will swell slightly when baked, while the burgers will shrink when baked. Cook the burgers in a non-stick pan until done.
Assemble the burgers by placing a slice of cheese, a burger meatball and ketchup between two buns and pierce with a toothpick to keep it together.
