In a large, heavy saucepan, combine 12 cups cold water, the cream and salt. Bring to a boil over high heat, and then reduce the heat to medium. Gradually whisk in the polenta in a slow, steady stream.
Whisk until the liquid boils again and the grains are suspended in the liquid. Keep whisking so the polenta doesn't scorch. Once it comes to a simmer, switch to a wooden spoon and stir every few minutes until the polenta is creamy without any hint of grittiness, 15 to 20 minutes. Remove from the heat and stir in the Fontina, Parmesan and nutmeg.
Line a table with butcher paper and pour the polenta onto the table, down the center. Serve with Basil Pesto Sauce and Bolognese Sauce. (These sauces also go great with pasta.)