In order to prepare the dough, pour the flour and a pinch of salt on the countertop.

Cut the butter into little cubes and add it to the flour. Then start kneading it with your fingertips until you get crumbly dough.

Dump the crumbs back on the countertop, mounded high like a mountain.

Then at the top push and scrape out the flout until it looks like a volcano. Add the water to this well and knead the dough fairly quickly before forming a ball out of it. Wrap it into cling film and refrigerate for 20 minutes.

After 20 minutes take the dough out of the refrigerator and roll it out.

Shape it depending your base and transfer it to it.

Now you shall cover the dough with baking paper and refrigerate it once more for 20 minutes.

Preheat the oven to 180°

Take the base out of the fridge and bake for 10 minutes.

Take the baking paper off the dough and bake again for 10 minutes until it gets golden brown.

Now you can start preparing the filling by chopping the onions first. Put the butter in your pan. Add the onions and cover them for 10 minutes. Uncover them and cook for another 10 minutes

Spread the baked dough with mustard, then add the onions.

In a middle-sized bowl whisk together the eggs and the cream.

Pour this mix over the onions.

Finally scatter the tart with the Parmesan.

Bake the tart for 40 minutes

Enjoy!!!!!!!