Season the monkfish tails with pepper only and then wrap in the Parma ham. Place the wrapped tails in an ovenproof dish and roast in a preheated oven, 190°C (375°F), Gas Mark 5, for 5 minutes. Pour the wine and lemon juice over, return to the oven and cook for a further 5 minutes.
Meanwhile, cook the potatoes in lightly salted boiling water with the mint sprigs for 10 minutes, or until tender. Drain, stir in a little of the butter and season with salt and pepper.
Cook the peas in salted boiling water. Drain the peas and crush lightly with the back of a fork. Stir in the remaining butter and the mint leaves. Season with salt and pepper.
Remove the fish from the oven and cut into 4 or 2, depending on how many tails you have. Serve the roasted monkfish on top of the crushed peas and with the new potatoes. Pour over a spoonful of the cooking juices.