For the lemon chicken, wash and dry the chicken. Rub with pepper and salt. Place in a roasting pan and roast in a heated oven for about 1 hour at 200° C (gas mark 3) until golden brown.
Meanwhile, wash the lemon hot and thinly grate the zest. Squeeze the juice from the lemon. Mix apricot jam, lemon zest and juice. Brush chicken with this glaze about 15 minutes before end of roasting time.
Wash and pit apricots and cut into bite-sized pieces. Peel onion and cut into quarters. Wash chard and coarsely chop leaves, chop stems into thin strips. Blanch in boiling water for 2 minutes, strain and drain.
Heat oil in a frying pan. Sauté onion until translucent. Add apricots and sauté briefly. Pour in apricot juice and steam for 3 to 4 minutes. Add the chard. Season with pepper and salt.
Remove the chicken from the oven. Pour a little gravy over the chard vegetables. Serve the lemon chicken on top of the vegetables and decorated with lemon slices.