Preheat oven to 200ºC (180ºC fan assisted oven)/400ºF/Gas 6.
Take out your Jus-Rol Puff Pastry Sheet and follow preparation instructions on pack to temper (bring to room temperature).
Heat the olive oil in a large saucepan, add the chicken and cook over a medium/high heat for 2-3 minutes.
Add the peppers, onion and garlic and continue to cook for 5-6 minutes stirring continually until the ingredients start to turn golden at the edges.
Add the fajita seasoning and cook for 1 minute then add the tomato sauce, season with salt and pepper and stir through. Allow the mixture to simmer gently for 1-2 minutes. Remove from the heat and allow to cool for 10 minutes.
Meanwhile, unroll the puff pastry sheet onto a lined baking sheet and spread the chicken mixture over the pastry, leaving a border of approx. 2cm to allow the pastry to rise. Brush the pastry boarder with beaten egg.
Scatter over the grated cheese and bake in the for 20 minutes until piping hot and the pastry is golden at the edges.
Allow to stand for 2-3 minutes before serving with a generous sprinkling of fresh coriander.