Combine the chicken stock and garlic in a large saucepan and bring to a boil over high heat. Reduce the heat to a simmer and very slowly add the cornmeal, whisking constantly to make sure there are no lumps. Switch to a wooden spoon, add 1½ tablespoons salt and 2 teaspoons pepper, and simmer over very low heat for 5 to 10 minutes, stirring almost constantly, until thick. (The timing will depend on the cornmeal that you choose.) Be sure to scrape the bottom of the pan thoroughly while you’re stirring. Off the heat, stir in the Parmesan, crème fraîche, and butter. Taste for seasonings and serve hot.