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 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 some water, then roll up firmly. Place the rolls on a baking tray lined with baking paper and bake in a preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for 20-30 minutes. Clean, wash and roughly cut the romaine lettuce into strips. For the vinaigrette, mix vinegar, oil and stock, add the rest oregano. Season with salt, pepper and 1 pinch of sugar. Mix salad and vinaigrette and arrange the rolls on top