Add oil and onion to a cooking pan, then add the cut broccoli head. After a few minutes you can add salt, pepper and some water. Let it cook for around 10 minutes.
In the meantime we can prepare the dough. Add the flour, yeast and salt to a bowl. Mix the water and oil in a different bowl - then start adding the flour mix, little by little while mixing all ingredients.
Knead the ingredients until you get a smooth dough that doesn’t stick to your hands.
Add the cooked broccoli, egg, mustard, sliced taleggio cheese and cottage cheese to a bowl and mix all ingredients. You can add another pinch of salt and pepper if you like.
Add some oil to a baking tray, then spread the dough with your hands. Cover it with the broccoli and cheese mixture and bend the side and corners of the dough as shown in the picture. Bake in the oven at 180 degrees (static) for around 45 minutes until the surface of the quiche gets golden. Let it rest 5 minutes before serving!