Chop the tomatoes into small pieces. Wash oregano, dab dry and chop the leaves finely. Clean and wash spring onion and cut into thin rings. Crumble cheese in a bowl. Add half of the oregano, tomatoes and spring onion and season with salt and pepper. Place the filling on the broad side of each triangle.
Brush the edges with a little water, then roll up firmly. Brush the rolls with oil and bake on a baking tray lined with baking paper in a preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for 20-30 minutes. Clean and wash the romaine lettuce and cut it roughly into strips. For the vinaigrette, put vinegar and the rest of the oregano in a bowl and fold in the oil. Then season to taste with salt, pepper and a little sugar. Mix salad and vinaigrette and arrange the rolls on top