Shashlik is actually nothing more than a grilled, often marinated meat skewer. The meat used is usually pork neck or back, but other types of meat are also possible.
There are mainly regional differences in the way it is prepared. In the Hungarian version, which is also a classic in Germany, paprika powder, paprika, onions and bacon are used.
But vegetarian versions with courgettes, mushrooms, peppers and onions or other vegetables are also possible and vegan at the same time.