Take the two sheets of puff pastry and roll it out flat. Cut off the edges so that it is even.
Now cut in the center to make two halves and further cut the two halves in half again, until you have four equal squares of rolled out dough.
Repeat with the other sheet of puff pastry. Now you will have 8 squares.
Fill each square with a teaspoon or two of the cooked and spiced onions. Add one egg half on top.
Roll the stuffed dough and pinch the edges together.
Brush milk on top of the rolled up raw egg puff. This helps the puff acquire a nice golden-brown crust.
Brush the tin pan with oil, and place the egg puffs inside.
Take a large pan, put a base plate in it and heat it.
Place the tin pan with the egg puffs on top of the base plate.
Cover and cook on low for 30-35 minutes.
The cooked egg puff would have risen and have a nice golden crust on top.
Serve warm with ketchup.