Pre-heat the oven to 190�C (375�F, gas mark 5). Peel the beetroot and cut into 2-3 cm chunks. Place in a roasting dish. Add 2 tablespoons of the olive oil and toss to combine. Cover the roasting tin with a sheet of kitchen foil and place in the pre-heated oven to roast for 30 minutes or until just tender. Remove from the oven and set to one side to cool.
Rinse the freekeh and steam (preferably) or boil then simmer for 15 minutes or until tender. Remove from the heat, drain through a sieve and run under cold water until cool. Set to one side.
While the freekeh is cooking, place the barberries in a bowl and cover with hot water. Leave for 10 minutes then drain.
Cut the halloumi in half lengthways, then slice each half crossways into thin slices. Pour 2 tablespoons of olive oil into a frying pan and place over a medium heat. Once the oil is hot, carefully add the halloumi slices (depending on the size of your pan you may need to fry them in batches). Cook for a couple of minutes on each side, until soft and slightly coloured. Remove from the pan and drain on kitchen paper and leave to cool.
For the dressing, whisk together the olive oil, tahini, lemon juice, lemon zest and garlic.
To assemble the salad, place the freekeh in a large bowl. Add the halloumi, beetroot, red onion, pine nuts, barberries, parsley and mint. Pour over the dressing and toss to combine.