Peak and nadir of Stephen Fry? (5)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

BROW (peak = the top of a hill) + last letter (bottom, in a down clue = nadir) of [stephe] N . Brown, as a verb = to cook food at a high temperature (for example by frying) to create a brown colour on the surface.