Put couscous in a large heatproof bowl, pour over stock, then cover with cling film for 5 mins until liquid is absorbed. Melt half the butter in a pan, then gently cook onion and garlic for 5-8 mins until soft. Set aside. Dry-fry pine nuts for a few mins until golden. Combine onions, pine nuts, apricots and herbs with couscous. Add a good squeeze of lemon
juice, season, then stir in egg. Leave to cool.
Using the back of a knife, stretch rashers to 1½ times their original length. Lay, slightly overlapping, on a large sheet of foil to form a rectangle. Make a few slashes in the thickest part of each chicken breast and lay between 2 sheets of cling film. Use the base of a heavy pan to bash the chicken until about 1cm thick. Arrange chicken over the bacon, fitting
so there are no gaps, but leave a border on longer sides. (This helps to roll up the chicken.)
Spoon stuffing over chicken in a strip along one of the longest sides. Using tin foil to help, roll bacon and chicken around stuffing like a log. Wrap tightly in foil, twisting the ends to secure, then chill for 2 hrs or up to 1 day.
Heat oven to 180C/fan 160C/gas 4. Place chicken, join-side down, in a roasting tray. Cook for 30 mins, then unwrap foil and brush roast with remaining butter. Cook, uncovered, for 20-30 mins more until cooked through, and the stuffing is hot (a metal skewer inserted into the chicken’s centre should come out hot). Cool and wrap in fresh foil to transport.