Bring the water to a boil in a 3-quart saucepan.

Beat the egg in a bowl with a fork, then stir in the groats.

Heat a wide skillet over medium heat, add the groats, and cook, stirring constantly until the grains are dry and separate, about 3 minutes.

Add them to the water with the butter and 1/2 teaspoon salt. Lower the heat and simmer, covered, until all the liquid is absorbed, 7 to 12 minutes-some brands cook more quickly than others.

Let stand for 5 minutes, then lightly fluff with a fork and season with pepper before serving.