Cook the parsnips in a saucepan of boiling water for 10 minutes. Add the apples and cook for 5 more minutes or until the apples and parsnips are tender. Drain and mash the parsnips and apples with the butter and a little seasoning. Allow to cool, spoon into a microwave-proof serving dish, cover with clingfilm and chill until required.
Meanwhile, make the marinade by mixing the oil, vinegar, honey and fennel seeds with a little seasoning in a shallow non-metallic dish. Add the pork and toss together. Cover and chill until required.
When ready to serve, thread the pork cubes and bay leaves, if using, on to 8 skewers. Arrange in a grill pan and cook under a preheated medium grill for 10 minutes, turning once or twice and spooning the marinade over until the pork is caramelized and cooked through.
Reheat the mash by piercing the clingfilm and cooking in a microwave on full power for 3–4 minutes until piping hot. Alternatively, return to a small saucepan and heat gently, stirring constantly, until hot. Spoon on to plates, top with the skewers and drizzle the pan juices over the top. Serve with steamed green beans, if liked.