Melt the butter in a heavy-based saucepan.
Add onions and sauté until translucent.
Add mince and fry until meat discolours, stirring with a fork.
Add tomato and seasoning, cover and allow to simmer for 15 minutes.
Remove lid and boil rapidly for 5 minutes or until liquid has evaporated.
Allow to cool.
Roll out one sheet of pastry on a baking sheet.
Sprinkle half of cheese over pastry.
Spoon filling on top of pastry, leaving 2 cm clear around the sides.
Sprinkle remaining cheese over filling.
Place whole boiled eggs on top of meat filling.
Brush sides with beaten egg.
Cover with second sheet of pastry, seal sides with a fork, or create a pattern using a knife.
Prick the top of pastry with a fork.
Brush with beaten egg and sprinkle with sesame seeds.
Bake at 200°C for 25 to 30 minutes or until golden brown.
Slice and serve warm with a crisp salad.