Cut throttle, turn off CT, manually trim up, turn rudder if able, and stick with it. You'll be surprised at how low you'll pull out of it... but you will.
If you're in the L model, deploy those "dive recovery flaps" PRIOR to the dive. Those things are a God send.
Above all, prepare and do you're best not to get into that predictiment to begin with.
Dont start your dive at 10k above the target, start at 5 or 6k at a low speed if possible. I try and begin the dive at less than 250mph (TAS). Ditto for Mossie, P47, and Tiff.
Good luck.