Finely chop the parsley, oregano, mint, red chilli and red onion and mince the garlic.
Transfer to a mixing bowl and add the red wine vinegar, sugar and 6 tablespoons of olive oil. Season with salt and pepper and stir to combine.
Season the chicken thigh fillets with salt and pepper. Place them in a cold frying pan, skin-side down.
Heat the frying pan over medium heat and cook the chicken undisturbed for 5 mins, or until the skin is deep golden brown. Flip and cook for a further 4 mins or until cooked through then transfer to a plate to rest.
Heat your oven grill to high. Halve the ciabatta rolls and toast under the grill.
Peel the avocados and thinly slice them.
To assemble, place a heap of rocket on the base of each sandwich. Add half an avocado and 1 red pepper and top with 2 chicken thigh fillets. Generously spoon over some of the chimichurri then finish with the top of the ciabatta. Tuck in and enjoy!
