Preheat the oven to 400F, 190?c, Gas 7. Butter a 13 x 9 x 2-inch glass-baking dish, mix the first 7 ingredients in large pan, and bring to simmer over a medium to high heat. Add half of the cheese, whisk until smooth. Chill the remaining cheese. Add the potatoes to the pan and bring back to a simmer, transfer the potato mixture to the prepared dish, spreading evenly, cover with foil and bake for 15 minutes. Uncover and bake until the potatoes are very tender and the liquid bubbles thickly, about 40 minutes. Dot the potatoes with the remaining cheese and bake until the cheese softens, about 5 minutes. Let cool for 10 minutes before serving. Serve and Enjoy!