In a shallow bowl, combine the egg whites, cornstarch and 2 teaspoons of the soy sauce. Add the chicken and a pinch each of salt and pepper and turn to coat. Refrigerate for 30 minutes.
Cut the pickled garlic and ginger into slivers. Seed the Scotch bonnet chile pickle and finely chop. Cut the remaining pickles into bite-size pieces.
Set a wok over high heat. Add the vegetable oil and heat until smoking. Add the pickled garlic and ginger and stir-fry for 10 seconds. Add the chicken and stir-fry until almost cooked through, about 3 minutes. Add the tomatoes and stir-fry for 1 minute. Add the pickled vegetables and chiles, pickling liquid and the remaining 2 tablespoons of soy sauce and stir-fry for 10 seconds to blend. Season with salt and pepper and stir in the sesame oil. Serve at once with steamed rice.