Excellent Question
That is a good question. It would depend on the power available for those airplanes (assuming two of the same type, ie, equal).
If it was an airplane that could maintain or gain energy while max-performing at corner velocity (possibly a Block 50 F-16 or Raptor), then come in at corner.
If it was like most airplanes, ie, even full-power will not sustain the corner, then coming in fast and bleeding it down in a pitch-to-slice would be the fastest turn. (This means start with a climbing turn [pitchback] then transition to a sliceback [descending turn]).