In a medium saucepan, bring the water and milk to a boil.
Whisk in the salt and the cornmeal and cook, still whisking, for 2 minutes.
Reduce the heat to low and cook, stirring occasionally, until the polenta has thickened, 45 minutes.
Stir in the 1/4 cup grated cheese and cook until the cheese has melted.
Lightly grease a 9-inch-square baking pan with olive oil.
Spoon all of the polenta into the prepared pan.
Refrigerate the polenta until quite cold and firm, about 4 hours.
To serve, heat the oven to 350 degrees Fahrenheit and lightly oil a sided sheet pan.
Cut the polenta into 4 squares and place on the sheet.
Drizzle with a little olive oil and bake until heated through.
Heat 2 tablespoons olive oil in a large sauté pan over medium heat.
Add the garlic and crushed red pepper and cook, stirring 2 minutes.
Add the tomatoes and cook 10 minutes.
Add the tomato sauce and bring to a boil.
Season to taste and keep warm.
Divide the mozzarella among the polenta.
Top with the tomato mixture and a little cheese.
Bake in the oven until the mozzarella is fully melted, 20 minutes.
Sprinkle with the basil and serve.