Preheat oven to 180 degrees.
Heat butter in a saucepan. Add the bay leaf and onion and fry for a couple of minutes.
Add the flour and fry again for a couple of minutes.
Add the milk and stir constantly avoiding lumps. The mixture will start to thicken.
Add in salt and pepper and switch off the flame.
Now add in the cheese and egg along with the cooked macaroni and mix well.
Arrange into a pan. Mix the melted butter, breadcrumbs and oregano. Sprinkle this over the macaroni.
Bake for 20 minutes. Sprinkle the coriander once hot out of the oven. Serve immediately.