Toppings listed below
In a heavy saucepan, bring the milk, water, bay leaf, salt and white pepper to a low boil. When the mixture reaches a boil, add the polenta, stirring vigorously with a wooden spoon to avoid lumps. When all of the polenta is incorporated, reduce the heat to low and continue stirring for 25 to 30 minutes, until the polenta pulls away from the sides of the pan or a finger pressed gently into the polenta comes out clean.
When the mixture is smooth, remove the pan from the heat and add the cheese and butter. Pour the batter into a flat pan and allow to cool. Divided into 4 equal portions of about 1 cup each, placing each portion between 2 sheets of plastic wrap. With the heel of your hand or with a rolling pin, press each portion of polenta into a circle about 6 to 7 inches in diameter. Remove the circles from the plastic wrap and set aside.
Preheat the oven to 350°.
Heat a large, heavy skillet over medium-high heat and coat with 2 tablespoons of the oil. Slide one of the polenta crusts into the skillet and cook gently until the underside turns light brown. Turn carefully and repeat, cooking about 4 minutes on the second side. Repeat with each crust and place on a large baking sheet. If desired, refrigerate or freeze crusts for later use.
Toppings
In a large bowl, combine the 4 cheeses. Divide the tomato slices among the pizza crusts, then sprinkle the cheeses on top. Place the pizzas in the preheated oven and cook for 10 to 12 minutes or until the cheese begins to bubble. Remove the pizzas from the oven and garnish with the olives, basil and anchovies. Drizzle each pizza with the remaining olive oil and serve immediately. Makes 4 main course servings.