To make the Monkeygland Sauce, heat the oil in a pan over a medium heat. Fry the onion, garlic and chilli until the onion is soft and nicely browned. Add the Worcester Sauce, chutney, tomatoes, tomato paste, vinegar and brown sugar to the cooked onions and mix well. Continue to cook over a low heat until the sauce has reduced down to a jam-like consistency (about 15 to 20 minutes). Remove from the heat and let the sauce cool down while you make the burgers.
Combine the mince, onion and garlic in a mixing bowl. Soak the bread in the milk and then gently squeeze out any excess milk. Add the bread mixture to the mince and season with salt and pepper. Knead the mixture together with your hands until well incorporated. Mould the mixture into 6 patties. The mixture is very wet but if handled carefully they will hold together nicely.
Using a small amount of sunflower oil, fry gently until cooked.
Assemble burgers, using additional extras and top with a generous helping of Monkeygland sauce.