Pre-heat the oven to 180C (390F) fan-forced and line a loaf tin with aluminium foil.
Place all the ingredients for the meat loaf in a large bowl and use your hands (with gloves so you don't get it under your fingernails) to mix it all together.
Press the mixture into the lined loaf tin and flatten out the top.
Cover with another sheet of foil.
Stand the tin in a shallow baking dish and very carefully pour 4cm of boiling water into the dish then put it all in the oven.
Bake for 70 minutes then remove the foil and drain off any excess liquid then return the loaf to the oven, uncovered for 10 minutes.
Leave it to rest in the tin for 30 minutes before serving.
Slices can be frozen individually wrapped.
To make the sauce, combine all the ingredients.