Cook the potatoes in lightly salted boiling water for about 20 minutes, until tender.
Meanwhile, heat 25g (1oz) butter with the olive oil in a large frying pan and add the pork fillet, cooking it for about 5 minutes over a medium-high heat until browned on both sides.
Reduce the heat and add the ginger, orange zest, orange juice and wine or stock. Season with salt and pepper.
Simmer gently for 10 minutes, then add the honey and cook for a few more minutes.
Cook the green beans in lightly salted boiling water for 4-5 minutes. Meanwhile, drain and mash the potatoes, then add the remaining butter, milk and mustard, beating well to mix. Serve the pork with the mustard mash and beans, spooning over the honey, orange and ginger sauce.
Tips: You could use ¼ tsp ground ginger instead of using root ginger – or you could leave it out altogether.