2. Beat the egg in a bowl with a fork, then stir in the kasha.
3. Heat a wide skillet over medium heat, add the kasha and cook, stirring until the grains are dry and separate (about 3 minutes). Add them to the boiling water, then add the butter and a dash of salt.
4. Lower the heat and simmer, covered, until all of the liquid is absorbed, about 7 to 12 minutes. Let stand 5 minutes before serving. Season with salt and pepper.