Marinate lamb with olive oil, rosemary, garlic and balsamic vinegar, salt and pepper for 2 hour.
Line a large baking tray with aluminum foil. Halve each capsicum. Remove and discard seeds and membrane. Cut each half into 4 slices lengthways. Place on prepared tray. Grill for 20 minutes, turning, or until tender and skin is blistered and blackened.
Transfer to a large heatproof bowl. Cover with plastic wrap. Set aside for 10 minutes. Peel and discard skin. Thinly slice. Return to bowl.
Preheat oven at 180 Celsius and roast lamb for 15 minutes or until reaches to desire doneness.
Transfer to a plate. Cover with foil. Rest for 5 minutes. Thinly slice.
Meanwhile, add haloumi to pan. Cook for 1 to 2 minutes each side or until golden.
Add lamb, haloumi, cucumber and spinach leaves to capsicum. Addsalad seasoning, little balsamic vinegar and remaining juices from the lamb. Toss to combine. Serve.