Next, make the polenta. Bring water to a boil in a medium saucepan over medium high heat. Add butter. While whisking gently, pour the polenta into the boiling water in a steady stream. Turn down heat to low and continue whisking until the polenta has thickened enough that it doesn't settle on the bottom of the pan. Cook polenta for 5-7 minutes over medium heat, stirring occasionally, making sure polenta doesn't get too thick. Keep adding small amounts of water if polenta gets too thick.