Step 1

Combine the vinegar, honey, garlic, chilli flakes, if using, and half the oregano in a shallow bowl or ceramic dish. Add the lamb and turn to coat. Cover and place in the fridge for 30 mins to develop the flavours.

Step 2

Heat a barbecue grill or chargrill on medium. Drizzle the lamb with oil. Cook for 12 mins each side for medium-rare or until the lamb is cooked to your liking. Transfer to a plate and cover with foil. Set aside for 5 mins to rest.

Step 3

Combine the cucumber, onion, lemon juice and remaining oregano in a small bowl. Season. Toss to combine.

Step 4

Thickly slice the lamb and serve with the cucumber and onion relish.