To fry the mushrooms, heat the oil and butter in a frying pan over a high heat until the butter is foaming. Add the mushrooms and fry for 4-5 minutes until they're golden.
To make the sauce, pour in the port or wine to deglaze the pan, then lower the heat and stir in the cranberry sauce until dissolved. Pour in the hot water and fruit juice and sprinkle in the bouillon powder or stock cube. Splash in a spoonful or so of soy sauce and stir well. Turn up the heat and boil the sauce rapidly for a few minutes until it reduces slightly.
Slide in the ham and heat through for a minute or two. Taste for seasoning and serve.