Preheat the oven to 190°C (375°F) (gas 5).
Add the cubed potatoes to a pan of boiling, salted water, bring back to a simmer and cook for 2 minutes to blanch. Drain and dry on a piece of kitchen paper.
Tip the potato cubes into a bowl. Add the paprika and chopped parsley. Season. Toss together until the cubes are coated with the paprika.
Now melt the butter in a shallow roasting tin or 1.2 litre (2 pint ) (5 cup) baking dish, about 2 minutes.
Carefully tip in the potato cubes and stir to coat with the butter.
Bake in the oven for 30 minutes, until the potatoes are tender, golden brown and crunchy round the edges.