Parkinson Cowan SLIPIN - Manual (Page 14)

Roasting
For best results we recommend open roasting using minimal fat or oil to
prevent splashing.
It is not necessary to cover meat or poultry or wrap food in foil when
roasting as this restricts the circulation of heat and will lead to extended
cooktimes.
If you are using a roasting bag or cover chicken breast with foil, be
prepared to allow an extra 10 - 15 minutes for each 1/2kg (1lb).
When cooking large items such as turkeys, the use of foil may be
required to prevent the breast becoming dry before the rest of the bird is
fully cooked.
R E N O W N D E L U X E S I
14
The oven