Fry together the bacon with the chopped onion for a few minutes, until the bacon is just cooked and the onion softened
Put the venison mince, cooked onion mix, 1 egg and seasoning into a bowl then mix well.
Preheat the oven to 200C/400F/180FAN/Gas6.
Cut a large piece of greaseproof paper to line a baking tray at least 30X20cm.
Lay out 1 layer, portrait style and quickly brush with butter or oil and then lay another sheet on top overlapping vertically by 2cm. Brush with oil and repeat with the remaining sheets.
Make the venison mixture into a long flattish sausage, about 8X24cm, and lay it on the filo pastry. There should be about 8-10cm at the top and bottom.
Now cut some diagonal slits in the pastry at the sides. Fold over the top edge and trim any excess, then use the side pieces to plait alternate pieces of pastry.
Brush with beaten egg mixed with the water and then bake for about 40 minutes until crispy and golden brown.
Notes
Top tips
If you have mixed the ingredients together and the venison still seems quite wet, add a tablespoon of plain or all purpose flour and check again.
If a little liquid comes out while cooking just use some kitchen paper to mop it up and then return to the oven to make sure that the bottom stays crisp