Liberally brush the tin or a large pudding basin/bowl with melted butterPlace a disc of baking parchment paper on the base of the tin (to prevent the pudding from sticking)
Fill the pudding tin with the pudding mixture (I use 1 x 2 litre tin, which will serve between 15-20 people). The mixture will fill the tin!
Take a 30cm square each of baking paper and aluminium foil. Brush the foil with melted butter, then place the baking paper on top of the foil. Now fold a 5cm pleat across the centre of the foil and paper, to allow for expansion. Place it on top of the pudding mixture (not too tight) and pinch around the sides of the tin, to secure it to the bowl. If you are cooking your Christmas pudding in a pudding bowl or basin, you will need to secure the foil by tying a piece of string tightly around the rim of the bowl. Place the pudding tin lid on top and click it into place
Place a trivet in the bottom of a very large, deep saucepan and place the pudding tin on top of the trivet. Add enough boiling water to the large pot, so that it comes up 2/3 of the pudding tin and creates a steam bath. Pop on the pot lid. Note: if making individual Christmas Puddings, you will need a wide, shallow pot with a lid and you will need to check the water level more often, to make sure you maintain enough water in the pot.
Allow the pudding to simmer for 6 hours, checking and topping up the water level every hour to make sure it’s still 2/3 up the side of the pudding. I set a timer! For smaller puddings: If using 2 x 1litre pudding tins, steam them for 4 hours. For mini puddings, you will only need 1.5 -2 hours
Once cooked, remove the pudding and set it aside to cool. I use a pudding tin with a loop on the lid -it’s easy to hook the cooked pudding out of the hot water. When the pudding has cooled, remove it from the tin (use a butter knife along the sides if it’s sticking)
Wrap the cooked pudding tightly in plastic wrap, then 2 coats of foil and store it in a cool place until Christmas. It can also be kept in the fridge or freezer for up to a year.