1. Mix the flours with sugar and salt in a large bowl. Add the cold butter in small pieces and cut with a knife or pastry blender into pea-sized pieces. Add some of the ice water and knead quickly with your hands until the dough starts coming together – add some more water if needed. The dough should not be sticky. Wrap in plastic wrap and place in the fridge for about 45 minutes.

2. Mix the ingredients for the sesame coating in a small bowl and set aside.

3. Preheat the oven to 200°C (390°F). Line a baking sheet with baking parchment and set aside. Make two equal-sized balls out of the dough and roll out each on a floured surface (size of a small plate) and transfer to the baking sheet. Slice the tomatoes as well as the spring onion. Spread one tablespoon of sour cream on each dough circle (leave about 5cm free on the edges). Crumble the feta cheese and sprinkle it on top of the sour cream. Place the tomato slices on top of the cheese, season with salt, pepper, and fresh thyme springs. Drizzle with some good olive oil.

4. To finish the galettes fold the edges of the dough towards the center to cover about 5cm of the topping. Pleat the dough every couple of centimeters to get a nice round shape. Brush the edges with whisked egg yolk and sprinkle with the sesame coating. Bake the galettes for about 25-30 minutes or until the edges are golden brown. Take out of the oven and let cool down for a moment. Serve still warm and drizzle some more olive oil over the galettes to finish them.