Work the flour, water and oil into a smooth dough using the dough hook of the mixer.
Let the dough rest for 30 minutes or roll it out very thinly to all corners on a baking sheet lined with baking paper and sprinkled with a little flour.
Mix the sour cream with salt and pepper and spread on the dough. Spread thinly sliced onions and pumpkin on top and sprinkle with chopped rosemary. Place the ham on top and pour a few dashes of olive oil over it. Bake in the oven for 15-20 minutes at 240 degrees.
Serve hot with a few arugula leaves and garnished with a few splashes of olive oil if necessary.