Mix the flour, dried yeast and salt in a bowl. Add the yoghurt, water and butter, mix, knead for approx. 10 mins. to form a soft dough. Cover the dough and leave to rise at room temperature for approx. 1½ hrs. until doubled in size.
On a lightly floured surface, roll the dough out thinly into a rectangle (approx. 40 x 50 cm). Spread the cheese over one half of the dough, place the other half on top, press down gently. Cut the dough lengthwise into approx. 2 cm strips, twist the strips and place on a baking tray lined with baking paper. Mix the butter with the garlic and herbs, use to glaze the cheese twists.
Approx. 30 mins. in the centre of an oven preheated to 180°C. Remove from the oven, leave to cool on a rack.
Heat the oil in a pan. Add the onion and dried tomatoes, sauté for approx. 5 mins. Add the tomatoes and sugar, season and bring to the boil, then reduce the heat and simmer for approx. 10 mins. Allow the sauce to cool slightly, puree. Serve the cheese twists with the dip.