Sprinkle both sides of lamb with cumin and garlic. Season. Spray a medium non-stick frying pan with olive oil, heat over medium-high heat and cook for lamb for 2-3 minutes each side or until cooked to your liking. Set aside on a plate loosely covered with foil to rest for 3 minutes. Slice lamb.
Spread base of sandwich with half the tzatziki. Top with rocket, beetroot, pickles, lamb and remaining tzatziki.
Season, sprinkle with coriander leaves and top with other slice of bread. Serve with sweet potato fries.
Leftover butterflied leg or sliced roast would also work well in this recipe.
Use any leftovers for lunch in a salad with remaining beetroot and leftover roast vegetables.
For a delicious pasta, add sliced lamb to a pan with cooked mushrooms. Toss through cooked pasta, baby rocket, ricotta and lemon zest.