Heat shallow pan over medium heat, add olive oil.
Wash and clean fish fillet and cut into chunks.
Drain well and season with salt and pepper.
Put flour in a shallow bowl and season lightly with salt and pepper as well.
Dredge fillets in seasoned flour and fry in the hot oil until brown, flip to cook the other side.
While fish is cooking, cut orange in half and squeeze the juice out or peel the orange and mash into a bowl.
Make sure that you're getting all the juices out.
Don't throw away the pulp, it's included in the sauce, set aside.
Transfer cooked fish on a serving platter, set aside.
In the same pan, add more oil if needed.
Then when oil gets hot, add garlic, onion and sesame seeds, cook until fragrant.
Add the juice and pulp of the orange, add about ⅓ cup of water to the pan.
Add honey or sugar and season with fish sauce and black pepper.
Bring to a boil, do a taste-test.
If you want a slightly thicker consistency, add a little of the remaining seasoned flour to the pan and stir briskly to avoid lumps.
If the seasoning and sauce consistency are okay with you, turn off heat and pour sauce over cooked fish fillet.
Garnish with parsley or green onions if using.
Serve hot with rice.