Preheat the oven to 180°C, fan 160°C, gas 4. Lay 4-5 basil leaves on top of 3 overlapping slices of pancetta and neatly wrap around 1 chicken breast. Repeat for the other chicken breasts.
Place the cous cous and chopped dried apricots in a bowl and top with 250ml boiling water. Cover with clingfilm and set aside for 10 minutes.
Meanwhile, heat the oil in a frying pan and cook the chicken for 3-4 minutes on each side, until the pancetta is crisp and the chicken is golden. Transfer to a baking tray and cook in the oven for 10 minutes, until the chicken is cooked through and no pink remains, then leave to rest.
Meanwhile, add the onion and courgette to the frying pan. Cook for 10 minutes over a medium heat, then stir into the couscous with the beans and tomatoes.
Serve the chicken with the couscous and drizzle the tzatziki over the top.