Preheat oven to 200°C. Spray the aubergine with the low calorie cooking spray until coated. Season well with salt and pepper. Wrap with aluminium foil and set on rimmed baking sheet. Roast until completely tender, turning once, about 30 minutes
Allow to cool slightly, remove from foil, and scrape flesh away from skin into a large bowl
Add soy sauce, anchovy, marmite (or fish sauce) to the aubergine and attack with a stick blender until smooth
Add the turkey mince and a good pinch of salt & pepper and mix well. It needs to be mixed very very well
Split mix into 4 and make into patties. Rough patties are fine, the mixture will be fairly wet. Place onto a baking try and bake for 20 minutes. Check centres are piping hot. they won't have browned much, you can sear them in a hot frying pan for a couple of minutes each side if you like
Serve on rolls with pickles and sauce