1. Pour the milk and water into a 2-quart saucepan, cover, and turn the head to medium-high. When the milk mixture boils (about 5 minutes), uncover the pot, add the grits and salt, and reduce the heat to medium. Stir constantly until the grits are the consistency of thick soup and release a fragrant sweet-corn perfume, about 8 minutes. Reduce the heat to low and simmer, stirring every 2 to 3 minutes, for about 20 minutes, until the grits thicken and fall lazily from the end of the spoon. Cook about 15 minutes more, stirring constantly to prevent the grits from sticking to the bottom of the pan.

2. When the grits are creamy and fluffy and soft, turn off the heat, add the pepper and butter, and stir to incorporate. Season to taste with salt and pepper, if desired, and serve immediately.