Preheat the oven to 200°C. Put the potatoes in a saucepan of salted cold water, bring to the boil and cook for 10 minutes, until just soft, but still holding their shape.
Drain in a colander and leave for 5 minutes, then toss gently in the colander to fluff up the edges. Put the potatoes on a baking tray and spray with plenty of low-calorie cooking spray. Sprinkle over the garlic granules, onion powder, salt and pepper, and toss to coat. Roast for 15 minutes.
Remove from the oven, shake and cook for a further 15 minutes until golden and crispy around the edges.
Add the spring onions, crumble over the Stilton, and pop back into the oven for 5-10 minutes until the cheese is melted and golden. Sprinkle over the parsley and serve!