Really easy mushroom risotto

INGREDIENTS

• 1 tbsp dried porcini
• 2 tbsp olive oil
• 1 onion
• 2 garlic
• 225g/8oz chestnut mushrooms
• 350g/12oz arborio rice
• 150ml/¼ pint dry white wine
• 1.2 litres/2 pints hot vegetable stock
• 2 tbsp chopped fresh parsley
• 25g/1oz butter
• Salt and freshly ground black pepper
• Freshly grated parmesan