In a large bowl, combine black bean sauce, vinegar, 1 teaspoon of arrowroot, and water in a bowl.
Pat fish fillets dry, then place in the bowl with remaining arrowroot.
Make sure to coat fish with arrowroot evenly on both sides.
Shake off excess arrowroot.
In a large skillet, warm oil over medium-high heat until smoking.
Add fish fillets and cook until browned and cooked through, about 3 mins.
on each side.
Place cooked fillets on a paper towel lined plate to absorb excess oil.
Add ginger and white scallion parts to empty skillet and cook until fragrant.
Add black bean mixture and simmer until thickened for about 1 minute.
Pour sauce over the fillets and top with scallion green parts and cilantro.
Serve and enjoy!.