Heat a frying pan until hot, then add the cumin and coriander seeds, peppercorns and dried chilli and toast for 1-2 minutes, shaking the pan from time to time. Pour the spices into a pestle and mortar and grind to a powder.
Transfer the spice mixture to a large bowl and add the olive oil, garlic, coriander root and mint. Mix well.
Add the rabbit loins to the bowl and stir to coat with the marinade. Massage well into the meat then set aside in a cool place for a few hours.
Heat a frying pan until hot. Wipe off the excess marinade from the rabbit and cook for 2-3 minutes on each side, or until cooked to your liking.
For the couscous, place the couscous into a bowl and pour over enough boiling water to just cover. Cover the bowl with cling film and set aside for five minutes.
Meanwhile, place the vinegar and sugar into a small saucepan and bring to a simmer. Simmer for one minute, or until the sugar has dissolved.
Remove from the heat and add the shallots. Stir well, then set aside.
Remove the cling film from the couscous and use a fork to fluff up and separate the grains.
Add the chopped piquillo peppers, pine nuts, coriander and mint and stir well.
Add the shallots and some of the vinegar mixture, to taste. Season, to taste, with salt and freshly ground black pepper.
To serve, place a spoonful of couscous into the centre of each of two serving plates. Slice the rabbit loins and arrange over the couscous. Spoon over any meat juices from the pan.