Step 1In a small saucepan, bring 4 cups of the water to a simmer. Keep this "backup" water hot, covered, over medium-low heat. In a 3-to 4-quart cast iron, enameled or other heavy saucepan, bring the remaining 4 cups water, the bay leaves and salt to a boil over medium-high heat. When it is boiling, add the olive oil.
Step 2Place the cornmeal in a wide bowl within reach of the stove. Scoop up a small handful of the cornmeal and, stirring constantly with a wooden spoon or flat-nosed spatula, let it sift slowly through your fingers into the seasoned boiling water. The cornmeal should fall like rain into the water. Sift the remaining cornmeal into the water a small handful at a time, stirring constantly and paying special attention to the edges of the pot. It should take about 5 minutes to add all the cornmeal.
Step 3When all the cornmeal has been added, the mixture should be smooth and thick and begin to "perk," meaning that large bubbles will rise to the surface. Reduce heat to medium-low-the polenta should continue to perk-and continue stirring until the mixture becomes too thick to stir easily, about 4 minutes. Add enough of the backup water-about 1 cup-to restore the mixture to a smooth stirring consistency. Stir again until the mixture is again too thick to stir easily. Continue adding the backup water and stirring like this until the cornmeal is tender, about 20 minutes from the time the cornmeal was added. As the polenta cooks, you will need to add less water each time and stir longer between additions. It is possible that you will not need to add all the water.
Step 4When the cornmeal is tender, stir the polenta without adding water until it is shiny and begins to gather around the spoon as you stir it, about 5 to 10 minutes. The polenta should be thick enough to stand a spoon in it. Remove bay leaves. Pour the polenta into a lightly buttered 2-inch-deep, 8-inch-round cake pan. Let stand until cool, then refrigerate (covered in plastic) until completely chilled, about 4 to 5 hours.
Step 1In a large pot over high heat, bring 4 quarts of salted water to a boil. Add the potatoes and cook 10 minutes.
Step 2Meanwhile, remove any wilted or yellow leaves from the cabbage and cut out the core. Cut the cabbage into 1-inch cubes. Add the cabbage to the pot and cook until both vegetables are tender, about 15 minutes. Drain thoroughly.
Step 3In a large skillet, heat the oil over medium heat. Add the garlic and cook, stirring, until it's lightly browned, about 3 minutes. Add the cabbage-potato mixture and season to taste with salt and pepper. Cook, turning the vegetables occasionally, until the liquid has evaporated and the vegetables begin to sizzle. Mash the vegetables coarsely with the spoon as you turn them, leaving plenty of lumps. Be careful not to scorch the mixture-cook it just until the liquid is gone. Remove the garlic cloves and season again with salt and pepper, if necessary.
Step 4Heat the oven to 400 degrees. Invert the cooled polenta cake onto a clean cutting board. Place toothpicks evenly around the perimeter in 2 layers to guide the knife. Use one smooth stroke or you will break the polenta. With a long, thin knife, slice the cake horizontally into 3 even layers. Place the top layer upside down in the bottom of a buttered 10x4-inch springform pan. Top with half of the potato-cabbage mixture and half of the Gorgonzola, spreading the filling smoothly as if you were icing a cake so that the layers are the same width. Top the cheese with the center layer of polenta and top that with the remaining cabbage mixture and Gorgonzola. Place the bottom layer of the polenta cake upside down over the torte and press gently. Melt the butter and brush the top of the torte with the butter and sprinkle with the grated Parmigiano-Reggiano. Use a spatula to smooth the sides of the torte.
Step 5Bake the torte until the top layer of the cheese is lightly browned and the torte is heated through, about 40 minutes. Remove the torte from the oven and cool for 5 minutes. Remove the sides of the springform pan and cut the torte into slices to serve.