How to make
Wash the potatoes and boil them in salted water until half boiled. Do not peel, but cut out a circle from the wide side. Hollow out the insides.
Make a filling from the stewed onions, mushrooms and ham and also add the carved out insides of the potatoes. When complete, place a tomato ring on the top, with a knob of butter.
Place them into a baking dish with a little water and bake in the oven. Finally, grate cheese over the boats and leave them for a few minutes to catch a crust.
