Toss the onion with half the lemon juice and some salt and pepper and set aside to lightly pickle.

Put the lamb in a bowl with the oregano, chilli flakes and olive oil. Season well. Place a sauté pan over a medium–high heat and fry the lamb for 3–4 minutes on each side until medium rare. Allow to rest for 5 minutes before slicing thinly.

In a bowl, use a fork to blend the remaining lemon juice with some salt and pepper and the extra-virgin olive oil. Add the lettuce, pickled onion, cucumber, tomatoes and olives and toss to combine, then gently stir through the feta.

Serve the salad topped with the sliced lamb.