If a chimney or other protrusion is under 1' wide, we would typically not build a cricket for it. In your case, with what looks like about 6" of exposure and open gable edge beside it, I sure wouldn't bother. I would buy L-shaped flashing designed for your metal roof type. You can step flash the side of the chimney (like it is currently but using only vertical pieces),cutting the mortar joints and re-pointing afterward, and then put one piece of L-flashing under those pieces. That would be the cleanest looking solution, I think. You can even buy pre-formed corner pieces now for the upper and lower corners.