Full power climb and corkscrew up keeping the turn tight and not standard.
Why corkscrew up - if you have been flying up a valley, presumably the valley goes straight on and turning either way might put you into the side, plus, even if you are current in flying IMC a corkscrew manouver can be very dissorientating - if you are flying there then you [I]should[I] have an idea where the valley goes after you become IMC, so climb doing your best to follow the center of the valley.
