Peel and cut the onion into eighths, and put into a freezer bag with the oil, mustard, dried sage, a good grinding of pepper, the lemon juice, the squeezed-out husks cut into eighths, and the Worcestershire sauce. Squidge everything around to mix (the mustard needs help to combine) and then add the chicken pieces. Leave to marinate in the fridge overnight, or for up to two days.
Preheat the oven to gas mark 7/220°C. Allow the chicken to come to room temperature in its marinade.
Arrange the chicken pieces in a roasting tin, skin-side up, with the marinade, including all the bits and pieces, and tuck the sausages around them. Sprinkle the fresh sage leaves over the chicken and sausages and then put the tin into the oven to cook for 1 hour and 15 minutes. Turn the sausages over halfway through to colour them evenly.
Arrange the chicken and sausages on a large platter.
Trending This Week