Pour the water into a saucepan and bring to the boil. Sprinkle in the polenta a little at a time, whisking continuously. When all the polenta has been added, cook for 2 minutes over a medium heat, whisking continuously. Pour in the cream and cook for a further 2 minutes Finely grate the Parmesan Gradually add the first quantity of cheese Add the butter Keep whisking until the polenta has thickened. Season with salt Pour the polenta into a large baking tray or heatproof dish. The polenta should be about 1cm deep. Leave the polenta to stand for 5 minutes and preheat the grill to high. Sprinkle with the second quantity of grated Parmesan Grill until the cheese is golden and bubbling. Serve Immediately. Tips: For the creamiest polenta, make it just before you want to serve it Look for the quick cook variety of polenta, which cooks in 5-10 minutes