1. First, make the dough; place the flour, oil, yogurt, and salt in a bowl, then knead until you obtain a homogeneous dough. Add more flour if necessary.
2. Flour the work surface, then roll out the dough to the size of your tart pan using a rolling pin. Prick the bottom of the tart with a fork, then blind bake for 10 minutes in a preheated oven at 180°C (350°F).
3. Meanwhile, mix the eggs, cheese, and milk in a large bowl. Season with salt and pepper.
4. Finely slice the onion and peppers, then mix them in the filling bowl. Spread the mixture over the prebaked tart crust, then arrange slices of goat cheese on top.
5. Bake for 35-40 minutes at 160°C (320°F). Storage: in the refrigerator for a maximum of 3 days.