Roasting part of a chicken?

[Ausflug]

I've bought a joint of chicken that is just the breast part, no legs or wings.

I want to roast it - can anyone tell me how long I should cook it for and at what temperature?

Also, there is no cavity to stuff, I don't think. Last time I roasted a chicken (some time ago) I put half a lemon in the cavity. Can I just balance it on top of a lemon instead? Or is there another way to make it taste a bit lemony?

About 40 mins on the lemon. Then squeeze it over for the last 5. Just check near the bone its done through

The basic rule for meat. 20 minutes per pound in weight plus 20 minutes.
Beef & lamb can be done less if you like it pink.

Thank you! I cooked it for 45 minutes balanced on top of the lemon, checked and the juices were running clear, gave everyone a piece of the caramelised lemon to squeeze over, and it was lovely! (DH and DD ate their whole piece of lemon, including the peel )
Very pleased with how easy it was to cook, will have to do it again!