Pull the fat away from the fillet and remove the sinew from the sirloin, then cut away the fat and the tail end of the sirloin. Cut the sirloin into approximately six portions, season to taste and set aside.
Place the roughly chopped Thai coriander, parsley and thyme in a flat container and roll the fillet over the herbs to coat. Season the fillet with salt and pepper. Set aside until ready to cook.
Meanwhile, for the sky potato salad, place the potatoes in a saucepan of salted water over high heat and bring to the boil. Cook for 15 minutes or until tender, then drain. Combine the warm potatoes with the onion, green spring onion, lime juice, garlic and olive oil. Season to taste and set aside.
Place the corn in a large saucepan of water over high heat and bring to the boil. Boil for 10 minutes or until just cooked. Drain, then set aside until ready to barbecue.
For the bean salad, blanch the beans in a saucepan of salted water, then drain and refresh in iced water. Drain again, then combine with the parsley, capers and olive oil. Season to taste and set aside.
For the salsa verde, place all the herbs in a blender, along with the capers, garlic, chilli, lime juice and olive oil. Season with salt and pepper and blend until well combined. Set aside until some of the oil separates from the herb mix.
Heat the hotplate of a barbecue until hot. Place the corn on the side of the hotplate and leave to cook for 8-10 minutes, turning once.
Take some of the oil from the salsa verde and brush it onto the hottest part of the hotplate. Place the meat on the prepared hotplate and brush with the salsa verde. Season with salt and pepper and leave to cook, turning once, for 8-10 minutes.
Remove the corn and the steak from the hotplate and leave the meat to rest for a few minutes. Serve with the grilled corn, potato salad and bean salad.