Mix flour, salt, olive oil, and warm water in a bowl until a dough forms. Shape into a ball.

Press the dough into a pie mold and prick it with a fork to prevent puffing.

Place the mold in a preheated oven at 180°C (350°F) for a short time while preparing the filling.

Sauté onion in butter until caramelized, then add bacon and cook.

Mix eggs, cream, and cheese in a bowl. Add the cooked onion and bacon mixture. Season with salt, pepper, and nutmeg (or mustard for a twist).

Pour the filling over the dough and bake at 180°C (350°F) for 45 minutes.

Let cool slightly, then serve with a fresh green salad.