We defrosted the berries we had that were in the freezer, they were just a mix from Waitrose and Tesco. We then washed and chopped our cooking apples. We placed all of this into a glass, oven proof dish trying not to get too many juices from the berry mix in as we didn't want it to damp. We then mixed in sugar to try and make it less sharp (we didn't actually put enough sugar in ours, it was really sharp!). Ours looked like this:
We then rolled out our left over pastry and placed it on top. We made a little slit in the top to let any steam out. We cooked it for about 30 minutes at 160c but the oven was already warm as it had just had our dinner cooking in it. It turned out like this.
Let me know if you recreate it, the measurements are very rough as we didn't really have an exact plan we started - we were just using leftovers up!