Boil plenty of water in a pot, add salt and cook spinach for around 3 mins. Drain water and cool it with water. Squeeze water and cut into small size.

Place some butter on a frying pan and start grilling salmon fillets. Cook both sides and steam for a while by covering with a lid. Once it’s cooked, place them on a tray and remove skin and bones. Crush the fish and make flakes.

Heat some butter in a pan and cook onions. Add flour and mix well. Add milk little by little and mix each time you add milk. Make a creamy white sauce. Add a chicken stock cube.

Add cooked pasta.

Place it in the heat resistant gratin container and put plenty of cheese on top to cover the surface.