For the base of the quiche, mix flour with water, salt and margarine. Knead well, cover the dough with cling film and leave in the refrigerator for 30 minutes.
Cut the tomatoes in half, salt and let them drain in a strainer. Grease a pie pan (ø 28 cm) with olive oil and dust with flour. Preheat oven to 180°C (convection oven). Roll out the dough, place it in the baking dish, form a rim of about 3 cm and prick it several times with a fork. Let it bake on the middle rack for about 10 minutes.
For the topping, blend Silken Tofu, olive oil, salt, turmeric, nutmeg and starch into a smooth paste. Season well with pepper and herbes de Provence. Pour the mixture into the pre-baked crust and distribute evenly. Press the tomatoes, curved-side up, into the silken tofu mixture. Bake on the middle rack for 20 minutes at 180°C (convection oven), then turn down the temperature and bake for another 15 minutes. Let it cool a bit before serving.