In a saucepot, bring the milk and water to a boil. Then, add the polenta in a slow steady stream, whisking constantly. Reduce the heat to low and cook for one hour, stirring frequently to prevent the bottom from sticking.

While the polenta is cooking, bring two cups of water to a boil along with the garlic cloves. Boil for five minutes, discard the water, add another two cups and bring to a boil again. Repeat this twice more. Drain the water completely and place the garlic in a small bowl. Add the butter and mash the garlic with a fork until it is smooth.

When the polenta is done, add the garlic puree. Season with salt and pepper, and serve immediately.