Make the polenta. Bring the water and the milk to a boil in a heavy bottom pan or dutch oven. Once the liquids are boiling, gradually whisk in the cornmeal. Reduce the heat to a simmer, then cover and allow it to cook for 25-30 minutes. Stir occassionally to avoid burning.
Roast the vegetables. While the polenta is cooking, preheat the oven to 425 degrees. Place the chopped vegetables on a parchment paper lined bakign sheet. Combine the olive oil, Italian seasoning, garlic powder, and salt in a small bowl. Brush the olive oil mixture onto the vegetables, then place them in the oven and cook for 20-25 minutes.
Finish the polenta. Once the polenta is thick and done cooking, remove it from the heat. Stir in the parmesan cheese, butter, garlic powder, and salt until the cheese has melted.
Serve. Put the polenta in the bottom of a bowl, then top with the roasted vegetables. Drizzle with olive oil, blasamic vinegar, or fresh herbs. Mangia!