Place aubergine in a microwave safe bowl and microwave on medium high for 3 minutes. Turn aubergine over and microwave another 2 minutes. The aubergines should be tender, but cook another 2 minutes if they are not. Drain any liquid from the aubergines and mash.
Combine cheese, breadcrumbs, eggs, parsley, onion, garlic, salt and pepper with the mashed aubergine. Mix well.
Shape the aubergine mixture into patties. Heat oil in a large frying pan. Drop aubergine patties one at a time into pan. Shallow fry both sides of each patty until golden brown, approximately 5 minutes on each side (turn only once). Patties can be frozen before frying and cooked later.
If you don't have Gruyère to hand, feel free to use Cheddar or any other cheese you wish.