Slice the eggs in half, wiping knife each time on a towel in order to keep the whites clean, and place yolks in a small mixing bowl.
Mash the yolks with a fork.
Add the oregano (1 teaspoon fresh), olive oil (2 tablespoons), vinegar (2 teaspoons), and salt and pepper. Mix thoroughly.
Distribute the yolk mixture evenly back into the egg whites.
Garnish with a sliced olive and some fresh oregano, and add a little more salt and freshly ground pepper as well.
The provided nutrition information does not include any added sodium from seasoning to taste, any optional ingredients, and it does not take brands into account. Feel free to calculate it yourself using this calculator or by adding the recipe to Yummly.