Prepare and slice the pork chop kasim and then transfer them to a bowl. Mix these with soy sauce, oyster sauce, calamansi juice, and some pepper. Mix well and let this marinate for an hour.
Cut the white onions into large rings. Set aside. Heat some oil in a pan and then sear the marinated pork (reserve the marinade). Flip to cook the other side. When both sides are nicely seared, remove them from the pan. Set aside.
Using the same pan, stir fry the onion rings for a few minutes. Then, add the seared pork back to the pan and saute them together. Add the reserved marinade and brown sugar. Stir well.
Cover the pan and let it simmer for a few minutes using low medium heat until the pork is completely tender. Add the rest of the onion rings and then toss for a minute. Transfer the pork steak to a serving plate. Enjoy this with a big bowl of hot steaming rice. Yum!