Preheat the oven to 200°C.
Finely chop the mint.
Wash and scrub the potatoes, then cut them into bite-sized pieces.
Peel and finely slice the onion, chop the garlic. Cut the tomatoes cut into thin wedges.
Place the potatoes, onion and half of the mint & garlic in a baking dish. Season with salt and pepper, add half of the oil. Massage oil into the potatoes, then arrange them evenly. Add the tomatoes, then pour over the vinegar and a teaspoon of water.
Bake in the oven for about 20-30 minutes. When the potatoes are tender and slightly roasted take the dish out of the oven.
Meanwhile, make a coarse paste with the remaining oil, mint and garlic. Rub the lamb steaks with this paste and marinate for about 20 minutes.
Heat a frying/griddle pan on the stove. Season the steaks with salt and pepper, then quickly seal them in the hot pan for a couple of minutes on each side.
When the potatoes are done, cover them with the steaks, sprinkle the olives around them, then returned the dish to the oven for 5-8 minutes.
Serve with chopped mint leaves scattered on the top.