Needed: potatoes (i made 2 for each personal and also cut a few smaller ones - the type of the potato affect the baking time), 2 tablespoon of olive oil, one stick of butter, cheese, garlic and rosemary according to your taste. For the non-vegan style you also can add some ham or bacon.
First wash the potatoes, you can peel them if you want, i found if i don't peel it the cheese doesn't run down from the top so much. Slice 3/4 trough in accordion style, be careful cos it is more difficult than it seems, at least for me it was. Place the potatoes on a baking pan. Warm up the oil and fry the finely sliced garlic but not too much. Then add the butter and mix it well until it melts. Cover the potato with the butter and make sure the butter gets between each slice. Then place the rosemary between the potatoes, put tiny pieces of the hame between the slices of the potato and add cheese on the top of each one. Bake it on 180°c until around 40 mins. Maybe you can add a little bit of water under the potatoes, so they can bake faster in the inside too.