1. Pre-heat your oven to 200 C/400 F.
2.Start with caramelizing the onions. Cut all of them into 3 mm slices. Heat olive oil in a non-stick pan on medium-low heat, add onions and sprinkle with salt. Let it caramelize for 35-40 minutes, stirring every 5 minutes or so.
3. Prepare the dough by first mixing flour with salt and baking powder, then adding oil and water. You should get a fairly smooth dough. Let it rest while the onion is caramelizing.
4. For the cream filling simply mix all ingredients.
5. Once the onion is done, roll out the dough into a half centimeter thick circle, spread the cream onto it, leaving a 3 cm border on the edge. Add onions on top.