Separate eggs. Mix egg yolks, flour, 3/4 teaspoon salt and water (or wine or beer) into a smooth batter. Let it soak for 30 minutes.
Cut the chicken into thin strips. Drain the lychees, collecting the juice. For the sauce, let the sugar caramelize lightly in a saucepan. Deglaze with the lychee juice and cook while stirring until the sugar has dissolved. Add the soy sauce, ginger and vinegar. Mix the starch with a little water and use it to thicken the sauce. Add lychees and heat.
Beat the egg white until stiff and fold into the batter. Heat plenty of oil in a pan. Pull the slices of meat through the dough in portions and fry until golden in the oil. Drain on a sheet of kitchen paper and serve with the lychee sauce.