Heat the olive oil and butter in a large, heavy-bottomed saucepan. Add the onion and cook over a medium heat for 7-10 minutes or until softened, stirring with a wooden spoon occasionally.

Stir in the rice and ham and cook for a further 5-7 minutes, or until the rice has lightly browned.

Pour in the dry white wine, bring to simmering point and simmer until the wine has been absorbed.

in a small bowl, combine 30 ml (2 tbsp) hot chicken stock and the powdered saffron. Blend with a wooden spoon to dissolve.

Add the remaining stock to the rice with the finely chopped mushrooms. Season to taste with salt and freshly ground black pepper and the grated nutmeg. Bring to simmering point, stirring constantly. Cover and simmer for a further 15 minutes.

Stir in the saffron and grated Parmesan cheese and correct the seasoning. Cook for a further 5 minutes, until the rice is tender.

Transfer the risotto to a heated serving dish. Fork up the rice grains, garnish with parsley and serve immediately.