1. Place the chicken fillet strips on a baking tray lined with parchment paper and bake in a preheated oven at 180 °C for 20-22 minutes.
2. In a small bowl put all the ingredients for the yogurt sauce -the yogurt, lemon juice, olive oil, salt and freshly ground pepper- and mix well.
3. On a cutting board, with a sharp knife, cut the tomatoes and the graviera into thin slices.
4. Lay out the tortillas on a cutting board, spread them with the yogurt sauce, arrange the graviera, then the tomato slices, and finally the chicken fillet strips.
5. Roll up tightly, cut in half slightly on the diagonal, and serve.
