Recipe from Americas Test Kitchen

  • 1.8L water
  • 1 1/2 teaspoons table salt
  • pinch baking soda
  • 1 1/2 cups coarse-ground polenta (see note)
  • 2 tablespoons unsalted butter
  • 4 ounces good-quality Parmesan cheese, grated (about 2 cups) plus extra for serving

Source