Grate the garlic and ginger.
Mix all ingredients in a large bowl with the Pisto Manchego. Add the sake, sesame oil, soy sauce and a pinch of salt and pepper.
To stuff the gyoza, make a ball with the mixture and place it in the centre of the wrapper. Wet half of the circumference of the inner perimeter of the wrapper and fold over to meet the other edge to make a half moon shape. Press both sides together with a fork, then using your finger make small pinch like impressions on the edge to seal the gyoza in a crest shape leaving the base flat.