Preheat the oven to 400ºF/200ºC. Toss the tomatoes and zucchini with one tablespoon of olive oil, season with salt and black pepper, and arrange in a single layer on a baking pan lined with parchment paper. Cook for 30 minutes, flipping halfway through.
Add the water, milk of choice, and salt to a medium pot. Bring to a boil over medium-high heat.
Once boiling, pour in the polenta with one hand while continuously whisking with the other hand. This helps prevent clumping. Reduce heat to low and simmer whisking often for about 5 minutes as the polenta starts to thicken.
Cover and cook for 25-30 minutes, stirring once every 5 minutes.
Taste the polenta to check for doneness. Once done, remove it from the heat, and stir in two tablespoons of butter. Put the lid back on for an additional 5 minutes (off the heat).
Serve it in a bowl with the roasted veggies on top, a drizzle of olive oil, fresh herbs, and a little salt. Plus any other additional toppings if desired.