Mix together the garlic, ginger, salt and soy sauce then rub the mixture all over the pork belly. Put the sliced onion into the bottom of your slow cooker and place the pork belly pieces on top. Cook on high for 4 hours.

Carefully take the pieces of pork belly out of the slow cooker then transfer them to a non-stick frying pan with a good spoonful of the cooking juices, turning occasionally. Let sizzle away on a high heat until all the sides are browned and the liquid has evaporated. Slice or cut into wedges and serve with mashed potato, steamed green vegetables and a gravy made with the cooking juices. Alternatively use in a ramen noodle broth, bao buns or in your own recipe.