In a medium saucepan over medium-high heat, combine the water and salt. Bring just to a boil then reduce the heat to low.
Gradually whisk in the polenta and ground black pepper. Continue whisking for 2 minutes, or until the mixture begins to tighten up.
Stir in the thyme, oregano, and 2 tablespoons butter. Continue stirring until well combined. The mixture will be very thick.
Butter a 10-inch springform pan then use a rubber spatula to spread the hot polenta in the pan, smoothing out the top.
Set aside to cool for 30 minutes, or until the polenta reaches room temperature. Cover the cooled polenta with plastic wrap then refrigerate for at least 2 hours and up to a day to set.
Preheat a grill to 400°F.
Open the clamps on the springform pan to release the polenta. Use a large knife or pizza cutter to cut the polenta into equal pie shapes.
Lightly oil the grill and brush each side of the polenta with olive oil.
Carefully place the polenta pieces onto the hot grill. Grill for 5 minutes on each side, or until nicely seared and golden in color.