1) Pre-heat pan with oil. Then add chicken portions for rendering till light brown in color. Set aside.
2) On the same pan, sauté onion and garlic till translucent. Add rendered chicken. Mix it well.
3) Add pineapple juice, sugar, soy sauce, oyster sauce, pineapple chunks and pepper. Let it simmer on a low-medium heat till the chicken is cooked and the sauce thickens. Ready to serve.