Peel and clean shrimp. Cut them in half.
Wash and dry them well. Put egg white on shrimp, and mix.
Mix 1 1/2 tbsp cornstarch and 1/2 tsp salt. Add to shrimp, and stir.
Add 1 1/2 tbsp oil, and mix well. Put in the fridge for 2 hours.
Take out the shrimp, and put the remaining cornstarch on them. Make sure they are dry.
Heat fryer to 350°F. Take off extra cornstarch, and separate shrimp.
Fry until golden brown. Mix with sauce, and toss to coat quickly.
To make sauce: mix sugar, salt, vinegar, catsup; keep aside.
Mix sherry and cornstarch; keep aside.
Heat 1 tsp oil in a wok; add garlic, ginger, zests, green onion, and red pepper.
Cook for 30 seconds; stir in catsup mix.
Right away, add the sherry mixture; cook until a bit thick.