Cut the turkey into even sized 3/4" cubes. Mix the dry sherry, soy, sesame oil and salt, then marinade the turkey in this mixture for 2 minutes.
Cut the pepper into the same size as the turkey and cut the spring onions into 3/4" sticks
Heat the oil
Dip the turkey into the corn flour and shake off any excess. Make a batter with the mixed egg and 2 tbsp of the corn flour. Place the turkey into it and coat. Carefully lift the turkey out of the batter and into the oil to deep fry until light brown. Take care not to fry too many at once. When golden brown take out and drain on paper.
Put stock, soy, sesame oil, vinegar and ketchup into a pan and bring to the boil. Add peppers and spring onions and simmer for 2 minutes. Mix in corn flour and Satsuma juice and pour in to thicken the stock, bring to the boil and simmer.
Mix well for one minute and serve.