Place the steaks in a bowl with the garlic, red wine and chilli flakes. Toss to coat, then cover and chill for 10 minutes to marinate.
Meanwhile, make the avocado salad. Combine the avocado, basil, cucumber and red onion in a bowl. Add the olive oil and vinegar, then toss to coat. Set aside.
Lightly oil a chargrill pan and set over a medium heat. When hot lift the steaks from the marinade, discarding any remaining marinade, and cook for 2-4 minutes each side, depending on how you like your steak done. Set aside on a plate to rest for a few minutes.
Divide the salad between the plates and top each with a steak to serve.View more Beef recipes...