How to butter-roast coffee in frying pan? I've starting roasting green coffee beans in a frying-pan at home and in a tin foil tray, when having an outside bbq.

What would be a good way to make a Vietnamese style butter-roast? Should I just fry the beans in butter, until they are brown?
Just frying them in butter won't work. The temperature needed to roast the bean is much higher than the milk solids can handle. If I were you, I'd begin by clarifying the butter to get rid of the milk solids, then use the clarified butter with the same method you are using now.

References:


Temperature scales for various roasts at the bottom
One way to make clarified butter