1. Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).
2. Roll out dough into a long rectangle and place it on a lined baking sheet.
3. Cut diagonal strips starting at the top, moving downward about one inch apart, going only a quarter of the way into the dough. Do the same thing on the other side, cutting the strips in the opposite direction.
4. In the center of the dough, in the portion that is not cut, spread a layer of pesto and cover evenly with tomatoes, cheese, and olives (if using).
5. Close the two rows of strips over the filling: Start on the right side and pull one strip across and downwards. Tuck it under the filling portion. Then take the top strip from the opposite side and pull it over the filling, tucking under the first side. Alternate both sides, pulling the strips across and slightly downwards.
6. Once fully closed, tuck both ends underneath and brush with egg wash.
7. Bake for 45 minutes. Serve warm straight from the oven or rewarm before serving.