Separate the egg whites from the yolks. Using an electric mixer, beat the egg whites with a pinch of salt until stiff peaks form. (The eggs should be at room temperature.)

Spoon the whipped egg whites onto a baking sheet lined with parchment paper. Make a small well in the center of each. Add a tablespoon of Parmesan cheese and a pinch of oregano to each well, then gently place a yolk in the center. Sprinkle with a little more salt and oregano, then bake.