First, wash and carefully remove the stalk of the Portobello mushrooms. Pat dry with kitchen paper, then place on a foil lined baking tray and drizzle with a little olive oil.
Place under a medium hot grill, and grill for 4-5 mins, or until the juices start to release from the mushrooms. Remove from gill and set aside.
Meanwhile, heat up half a tablespoon olive oil, and add the red onion, red chilli, and grated garlic and sweat for 4-5 minutes until soft. Add the balsamic vinegar, season well with sea salt and freshly milled black pepper, and mix thoroughly.
Next, carefully stuff in inside of each mushroom with the onion/chilli/garlic mixture.
Then, cover with halloumi cheese slices and trim the pieces into shape so that the onion topping is complete covered.
Return the mushrooms to a medium-high grill, and grill until the cheese turns a golden brown.
Remove from grill, then season and garnish with flat leaf parsley.
