Remove from heat and strain the oil into a bowl, discarding solids.
In a skillet, heat enough vegetable oil to coat the bottom over medium-high heat. Place fillets skin-side down and cook for 4-5 minutes until skin is crispy.
Carefully flip the fillets and cook for an additional 3-4 minutes until flesh is opaque.
Remove from skillet and place on a paper towel-lined plate to absorb excess oil.
Drizzle ginger oil over the fillets and garnish with green parts of spring onions.
Serve with steamed jasmine rice or a fresh salad.
Notes
For variations, consider adding chili for heat or citrus for brightness.