Start by preparing the ingredients. Tear the oyster mushrooms by hand into lengthwise strips. Crack the eggs into a bowl and beat them lightly with a fork. Finely chop the fresh parsley and grate the Pecorino Romano in advance so you can work quickly while cooking.
Melt the tablespoon of butter in a frying pan over medium-high heat. Wait until the butter foams and then add the oyster mushrooms. Cook the mushrooms without stirring constantly, so they have a chance to turn golden brown and slightly crispy at the edges.
Lower the heat once the oyster mushrooms have the right color. Pour the beaten eggs into the pan and distribute the grated Pecorino directly over them. Push the egg mixture gently from the edges toward the center of the pan with a spatula. Keep repeating this slowly until the eggs are just set but still look soft and creamy. Remove the pan from the heat immediately.
Divide the scrambled eggs with oyster mushrooms between two plates. Sprinkle the finely chopped fresh parsley over the dish and add a pinch of black pepper to taste. Serve immediately.