Mix the shredded chicken with the soy sauce, sesame oil and the egg. Cover and put it in the refrigerator to marinate for 2 hours (at least).
Before frying them, mix the chicken with the starch and the plain flour.
Heat olive oil in a pan or wok, and bake or fry the chicken chunks on high temperature. They will get brown and crunchy. Put them aside.
Cut the pineapple into pieces and slice the bell pepper into small strips.
Heat the juice of the pineapple in a pan and cook the pineapple pieces and the bell pepper in it.
Add the brown sugar and the soy sauce.
Dissolve the starch in the water, and add the mixture to the sauce. Let it integrate and thicken.
Add the chicken chunks to the sauce and mix everything well.
Serve while hot with rice.