Place the curd, milk, oil and salt in a mixing bowl and work into a smooth mixture with the dough hooks of the hand mixer. Mix flour and baking powder, add and knead until a smooth dough is obtained. Peel and finely dice the onion. Wash, clean and chop the mushrooms. Wash the tomatoes and cut out the stem.
Cut tomatoes, except 1 for garnishing, in half, remove seeds and cut into small cubes. Wash chives and cut into fine rolls, except for 1/2 bunch. Mix onions, mushrooms, diced tomatoes, chives, sunflower seeds and Roquefort cream, season with salt and pepper. Roll out a thin layer of quark oil dough on a floured work surface and cut out 8 circles (approx. 18 cm Ø). Spread the filling over the middle of the pastry sheets. Press the dough over the filling to form small bags. Wrap 2 of the remaining chive stalks around each bag and tie up. Whisk the egg yolk and 1 tablespoon of water and brush the sachets with it. Place on a baking tray lined with baking paper and bake in a preheated oven (electric range: 175 °C/ gas: level 2) for approx. 30 minutes. Clean and wash the frisée salad and place it on a serving dish.
Press the dough over the filling to form small bags. Wrap 2 of the remaining chive stalks around each bag and tie up. Whisk the egg yolk and 1 tablespoon of water and brush the sachets with it. Place on a baking tray lined with baking paper and bake in a preheated oven (electric range: 175 °C/ gas: level 2) for approx. 30 minutes. Clean and wash the frisée salad and place it on a serving dish. Cut the rest of the tomato into eighths. Arrange the pastry bag and tomato cake on the salad and serve