Polenta with Arugula

8 cups water

1 1/2 teaspoons salt, plus more to taste

1 1/2 cups quick-cooking polenta (pre-cooked maize meal)

2 garlic cloves, minced

3 cups arugula, coarsely chopped

1 stick butter

1/2 cup whipping cream

3/4 cup freshly grated Parmesan, optional

Combine the water and salt in a heavy large saucepan. Bring the water to a boil over high heat. Gradually whisk in the polenta. Decrease the heat to medium-low. Stir constantly until polenta thickens, about 5 minutes. Add the garlic and arugula, and stir until the arugula is wilted. Stir in the butter, cream, and cheese, if using. Season the polenta, to taste, with salt and pepper.