Preheat the oven to 180 (fan). In a medium saucepan over a medium heat add Frylight to cover the base of the pan. Once warm add the chopped onions and cook whilst stirring occasionally for around 4-5 minutes until they soften and begin to turn translucent.

Add in the beef mince and break up into small pieces in the saucepan and mix together with the onions. Season with salt and pepper. Add a couple more sprays of Frylight if it's needed so the meat doesn't dry out or stick to the pan. Once the meat is browned add the dry herbs and garlic and combine.

Boil 100ml of water and set aside. Add in the chopped tomato to the saucepan. Cook for another minute whilst stirring occasionally. Add the beef gravy granules and Worcester sauce then the boiled water, stir everything together. Leave to simmer over a medium to low heat until the sauce reduces by half and thickens.

Turn off the hob and set the meat mixture aside. Take the ready made mash, (you can of course make your own, but this is for convenience in this instance and it's available to buy in the fresh section of most supermarkets). Microwave the mash for two minutes to soften. Add the butter to the mash plus a little salt and pepper to season and give a mix so it's a nice soft, smooth consistency.

Spoon the meat mixture into a perspex/oven proof dish, and even out flat with the back of a spoon. Next add the fluffy mash on top, and using a fork neatly take it right up to the sides so it completely covers the meat layer and there's no gaps, this is to prevent leaks. Sprinkle over the grated cheese neatly, right up to the edges.