Preheat the oven to 180 degrees Celsius (356 degrees Fahrenheit) C.
Put all ingredients in a bowl and mix them together with a hand mixer with dough hooks. Knead finished on a floured surface, the dough should be smooth and pliable.
Place the dough in the fridge for 15 minutes, then roll it out into a tart crust and place it in a greased tart tin.
Filling
Slice the potatoes and spread them on the base. Sprinkle the cheese on top.
Mix the egg mixture together and pour it in.
Place the tomato slices and ham on top and sprinkle with finely chopped fresh rosemary.
Bake for about 40 minutes until the egg is set and the edges are golden.