Wash and dry the potato thoroughly in its skin. Then prick the potato in several places with a fork. Transfer the potato onto a baking sheet lined with parchment paper and put it into an oven preheated to 190°C (374°F). Bake until medium soft, which takes about 35-45 minutes (depending on the size of the potato). Near the end of baking, prepare the remaining ingredients.

Grate the cheese on a grater or finely chop it. Peel and finely chop the onion.

Remove the potato and let it cool slightly. Then cut it lengthwise in half. Gently scoop out some of the pulp from the center of each half with a spoon. In a bowl, place the crumbled pulp, cheese, and onion. Season to taste with salt and pepper and mix thoroughly.

Fill each potato half with the stuffing and return to the oven. Bake until the potatoes are soft and the cheese has melted, about 10 more minutes.

Eat immediately after preparation.